第一篇：機械專業英語翻譯——推薦書籍

口語貓英語 · 在家上外教課

https://kouyumao.com 機械專業英語翻譯——推薦書籍

隨著國際交往日益增多，我國進出口產品與日俱增。在與外方交流過程中，正確使用機械專業英語術語相當重要，否則人家聽不懂你在講什么。如“hypoid gear”，國內常用英漢詞典就有譯名：雙曲線齒輪、準雙曲面螺旋錐齒輪、準雙曲面齒輪、偏軸傘齒輪、直角交錯軸雙曲面齒輪、海波齒輪（音譯）等，不懂機械專業英語翻譯的同學就會不知所措，現譯名為“準雙曲面齒輪”。同學們在翻譯機械專業英語的學習資料時，如果翻譯不準確也會發生很多問題。在進行機械專業英語翻譯時小伙伴們需要結合應用場合準確翻譯，比如“crossed helical gear”譯為螺旋齒輪不妥，應譯為“交錯軸斜齒輪”、“standard pitch diameter”應譯為分度圓直徑而不宜譯為標準節圓直徑，對單個齒輪而言只有分度圓沒有節圓；而“working(or operating)pitch diameter”應譯為嚙合節圓直徑。再比如系數，在幾何量上用“coefficient”,如“addendum modification coefficient”應該翻譯成徑向變位系數；在強度方面用“factor”,如“application factor”是使用系數的意思；“overload factor“為過載系數；”dynamic factor“為動載系數。凡此種種都要求翻譯術語規范化，符合國情便于交流。

口語貓英語 · 在家上外教課

https://kouyumao.com 所以就推薦幾本機械專業英語的書給有需要的小伙伴們：

1、《英

漢

機

械

工

程

常

用

詞

匯

》

這本書主要介紹英漢機械工程常用詞匯，所以在一定程度上可以幫助讀者準確地閱讀英文專業文獻以及進行機械領域方面簡單的英文交流。內容主要包括數學、數學表達式和方程式、物理學、化學、機械制圖、公差與配合、理論力學、材料力學、機械原理、機械零部件、金屬材料與熱處理、電工學、切削加工、液壓傳動等等

內

容。

這本書的編排合理、內容實用且查詢方便是一本參考性極強的工具書。

2、《圖解機械制造專業英語（增強版）》 這本書具有系統、呈面、簡明、形象之特色。對于已經學習過專業課程的讀者來說可以溫故而知“英”，而且還可以擴大已有的關于機械的知識面、開闊技術視野；對于非機類專業人士來說可以簡單學習專業術語、名稱并認識機械各類零件、結構、設備和加工方法，所以這本書也便于給機械初學者進行自學和應用于實際工作。這本書不僅適合作為機械類專業的大、中專院校的專業英語教材，也可供機類及非機類專業從事技術翻譯、技術交流、進出口貿易等工作的各界涉外人士、工礦企業的專業技術人員學習參考。

第二篇：機械專業英語翻譯

第一單元 極限與公差

幾何精度設計是在機械制圖上使用的一個三維國際工程設計語言。這個語言主要由符號組成，這些符號是清楚地定義在由美國機械工程協會出版的ASME Y14.5M-1994中。這個制圖標準在北美使用和全世界都認同。它代替了更早的ANSI Y14.5M-1982標準和已經發展到幾乎等同于它的ISO副本。這個標準在確定使用各種幾何符號的方式和在清楚地展示設計者的意圖的其他方法上是完善的。

幾何精度設計的合理使用保證了工程設計想要的形狀、配合和功能，沒有在車間的假想或每個人都詮釋不同的精細制作的筆記。幾何精度設計將通過在整個工程設計、制造和品質功能中提供相同的解釋，增加制造公差，提升效率和品質來節約公司花銷。我們的經驗表明許多設計者、車間和品質控制人員，盡管在幾何精度設計工作了許多年，但還是沒有完全了解要求和沒有利用到幾何精度設計的所有優點。

設計和生產系統，復雜性，電算化，和全球制造對準確的工程圖紙提出了強制性要求。功能測量，刀具，零件尺寸和制造受益于幾何精度設計。幾何精度設計的學習是重要的，因為它是設計、制造過程和質量三者溝通的粘合劑。

制造，設計系統需要一個易懂的語言，否則，它是不一致的和不可用的。一門技術語言被定義為一個標準，這個被廣泛使用的標準是ASME Y14.5M-1994。我們的目的是讓幾何精度設計和制造過程協調一致。你可以已經在計算機輔助設計課或制圖課上接觸到幾何精度設計。

第二單元

力學概論

力學的基本概念：

力學是用來處理運動，時間和力的科學分析的分支，它由靜力學和動力學組成。靜力學研究靜態系統的分析，這時，時間不是一個考慮的因素;動力學則是隨時間變化的系統。力是通過相配合的表面傳遞到機器各個構件的。例如，從齒輪到軸或一個齒輪通過嚙合齒傳動到另一個齒輪或連桿通過軸承傳到杠桿，從V帶到滾輪或從凸輪到傳動件。有許多理由都必須知道力的大小。力在邊界及配合表面的分布必須要合理，其強度必須在構成表面的材料的工作極限內。例如，如果作用在套筒軸承上的力太大，將會把油膜擠出，并導致金屬表面的膠合，過熱和軸承過快失效，動力學的研究主要是確定李的大小、時間和位置。

下面將說明一下我們這方面的研究

力：我們最早的關于力的想法是源于我們對推、舉和拉河中物體的需要。因此力是一個物體對另一個物體的作用。自覺對力的聯系包括力作用的位置，方向和大小，這些稱為力的特性。

物質：物質是一種材料或實物，如果它完全封閉則稱為物體。

質量：牛頓吧質量定義為物體的數量，由體積和密度來衡量。這定義并不是很多人滿意的，因為密度是單位體積的質量。通過猜想我們可以諒解牛頓，可能他并不認為那是個定義。然而，他已經認識到了一個事實，那就是所有的物體都具有不同于重量的內在性質。所以，盡管月球重量不同于地球重量，但一塊月球上的巖石仍有特定不變的本質數量。這個恒定的本質數量或物質食糧就是巖石的質量。

國際單位制最大的有點事它對任何物體有且僅有一個單位。長度的單位為米，質量的單位為千克，力的單位為牛頓，時間的單位為秒等等。為了和這種特性保持一致，就要求一個給定的單位或詞不能僅一個被認可的技術名稱在二個物理量中使用。然而，習慣叫做“重量”的這個詞已經在技術和非技術領域廣泛使用，表示著物體所受的引力和其本身質量。

粒子：粒子就是指尺寸小到可以忽略的物體。

剛體：物體要么是彈性的，要么是塑性的，只要作用上力都會產生變形。當物體形變量很小時，通常將其假想為剛體，即沒有變形的能力，作此假想以便簡化分析。

可變形的物體，作為應力和應變是由將要分析的作用力所提供的，則剛體假說將不再適用。因此我們認為物體時可變形的。這種分析常稱為彈性物體分析，兵并應用這附加的假說，即在力作用范圍內，物體仍保持彈性。

牛頓定律，牛頓三大定律是：

牛頓第一定律：如果一對平衡力作用在一個質點上，那么這個質點仍將保持靜止或勻速直線運動。

牛頓第二定律：如果作用在質點上的力不是平衡的，則該質點將經歷一個加速度且加速度與合理大小成比例，沿合力方向。

牛頓第三定律：當一對質點相互作用，作用力與反作用力其大小相同，方向相反，作用在過二個質點的直線上。

2，力和力矩：

當一個物體從一個組成系統中聚集到一起，任意兩物體間相互作用的力稱為約束力。約束力使物體以特定的方式運動。作用在系統上的力稱為作用力。

有的力在作用中并沒有實際的物理接觸。例如，電力磁力和引力。有許多，但不是大多數的力我們會涉及到。這些力是通過物理的或機械上的接觸相互作用的。

力是個矢量，力的要素是：力的大小，方向和作用點。力的方向包括那條沿力的指向為方向的直線。因此力可能沿直線正向，也可能沿直線反向。二個大小相等，方向相反，作用不共線的合力。任意二個這種力作用在物體上將會形成一個力偶，力臂是作用線的垂直距離，作用和面是通過二個作用力的平面。

第三單元

簡單機械

圖3-1給出了直杠的三種布置情況，每個例子中Ｆ是支點；Ｐ是作用力，作用在ｂ點上；Ｗ是載荷，作用在ｃ點上，當杠桿處于平衡時，為Ｐ使杠桿繞ｆ轉動的趨勢必須與載荷ｗ使杠桿往反方向旋轉的趨勢相平衡。忽略在支點上的摩擦力，以上關系可用數學式表達為：Ｐ＊ＢＦ＝ＷＸ從上式可以看出，施加的作用力乘以支點到一作用點應等于另一側的乘積，從這可以導出“機械效率”這個量，它等于載荷除以作用力：

機械效率＝Ｗ／Ｐ＝ｂｆ／ｃｆ

圖３－１Ａ中如果ｂｆ／ｃｆ＝３，就意味著３０磅的載荷能被１０磅的為所平衡。如果力稍超過這個數值，杠桿將會隨著為Ｐ的增大而繞點ｆ旋轉，為Ｐ比載荷Ｗ增加得更快更大，這也是機械效率，但應忽略摩擦力的作用，顯然，ｆ、ｃ間的距離越短，杠桿的力放大八月入越大。

圖３－１Ａ的布置情況可在鉗子和剪刀上找到，而圖３－１Ｂ的情況可在手推車中找到，ｆ相相當是車輪，Ｗ為載荷，力Ｐ由操作者施加在手柄上。圖３－１Ｃ中，杠桿的作用于是作為一種運動放大裝置，它用在腳踏板上來驅動一些小機械。腳踏板上ｂ的小運動可在ｃ產生大運動。

圖３－１Ｄ中所示的差動滑輪就是基于杠桿原理。半徑為Ｒ的輪Ａ和半徑為ｒ的輪Ｂ固定在軸上，并可以轉動。力Ｐ是由一條位于輪邊緣一個槽中的繩子所提供的，載荷 W由繞在驅動軸上的繩子來提升。當驅動軸靜止時，力P促使軸的轉動趨勢與W促使軸的轉動趨勢相等，且方向相反。忽略軸承摩擦力的話，力P和大輪半徑R的乘積將等于載荷W與驅動軸半徑的乘積：P*R=w*r 機械效率還是等于W/P，也等于輪R與驅動軸R的比值。

這種情況和杠桿類似。然而杠桿只能移動載荷很短的距離。而差動滑輪能移動開荷 的距離，只限制于線強長度。

當輪A和繩由裝輻條的輪代替時，差動涔輪就僅適于從井里提升一桶桶的水。然而更重要的是差動滑輪的原理在許多工具和機械中是很顯而易見的。例如，螺刀，由手提供的力作用在大半徑上就能在小半徑上轉化出很大的力作用在螺釘上。

滑輪是一種最基本的簡單機械之一。它從根本上說是由一個輪子和一個支承組成，輪子的輪邊帶有槽，槽上繞著柔軟的繩子，而支承有如固定的或可動的軸承組，一個往下的拉力會產生一個大小相同的向上的力。圖3-1E中滑輪和可動組B結合時，如果飯略摩察力的話，繩中所有點的張力P是一樣的，因此在繩松開的這邊給定一個向下的拉力，將可以提起這個拉力兩倍的重物W，而重物W的上升速度交為繩移動速度的一半。因此機械效率為2倍，若使用種種帶有固定的和可動的軸承組的滑輪組合，那機械效率將比2倍還要大。例如熟知的軸承級和滑車組合就是一種基本的力放大裝置。

現在來考慮一下圖3-2中楔的運動。它由力P向左邊擊打。當角度Q越小，摩擦力F也越小時，以r表示的分力N將會越大。對于任一楔表面的粗糙度以及對奕的摩托車擦力，如果角Q大于一個給定值，即使力P撤掉后，楔仍會保持原位或像粘住了。

可楔緊的錐度在機床主軸中常用來夾撫持切削刀具，如鉆頭鉸刀。其它應用楔原理的機械裝置有木刨，子，刀，金屬世削刀具和凸輪

絲杠可以認為是楔錐在一個圓柱體上。絲杠是由在實心圓柱上切削出連續不斷的槽所形成的，這些被實心材料分開的，連續的，圓周的槽稱為螺紋。螺紋和槽都是螺旋形的。

如果將圖3-3右側所示的圖ACC`A`H上線段AB`和BD 在左側直徑為d的圓柱上，將會形成1。5圖的螺旋。其對應的軸向距離l稱為導程。導程角λ是用來度量螺旋的傾斜角。

一些早期的螺釘，其切削方法類似于用展開的如圖3-3左邊的螺旋一條柔軟的金屬薄板，以右螺角形式，纏繞在圓柱形毛坯上，以便右角的一臂能平行于軸線，斜邊用在圓柱上形成螺旋，用作切削螺旋槽的導向。

如果滑動無件被約束為沿平行圓柱軸線運動，如圖3-3中的F，沿著軸線00`運動，它就能被圓柱體的旋轉、螺旋或是拉直螺旋的平移所驅動。另一種情況，楔的運動是很明顯的。如果螺帽的一部分構件F，它限制了旋轉運動但軸向運動是自由的，絲桿螺帽組合將會把螺旋運動轉化成

第四單元

機構

基本類型

機構的目的是為了傳遞運動，而不管機構有沒有變更。雖然機構有許多中組成形式，但總的來說只有三種分類，如圖4-1所示

圖中的每種機構，桿2和桿4都是通過O點和Q點聯接到桿1的。這兩種機構的運動傳遞方式如圖4-1所示：（A）通過柔性的包裹聯接器傳遞，如皮帶，繩子，纜和鏈條等；（B）通過直接接觸傳遞，如用凸輪，齒輪或是摩擦輪；（C）用剛性的聯接桿或聯軸器傳遞。在各種情況中桿2都是驅動件，它以每分鐘n2轉的轉速轉動，而桿4是從動件，以每分鐘n4的轉速轉動，對于這三種情況，桿2和桿4的轉速比是由Of的長度與Qf的長度比值所決定的。圖4-1A中由于點f固定與OQ的中心，所以它的速率是一個常量，在圖4-1B和4-1C中，由于點f將會隨著物體的轉動而移動，故其速率是變化的。直接接觸的物體能設計成只會擺動，如圖4-1B，或只會持續轉動。在所有的情況中，點f都是位于有公法線和中心線的交點上。

直接接觸機構

在大多數的情況中，直接接觸的表面互相之間是滑動的，并僅僅只有滑動運動。這樣表面情況是很容易惡化的。而在特定的條件下，表面磨損不厲害的純滾動接觸具有更高的效率。如果其他條件滿足了，物體將會以勻速傳遞運動。這些特定的情況在齒輪聯接和凸輪聯接中是很有用的。純滾動的條件是接觸點位于中心線上。

共有三種純滾動接觸的情況，當兩物體是圓柱體時，公法線和中心線是重合的，所能傳遞的載荷是由其表面摩擦所決定的，這就是所謂的基于摩擦的滾動。對于不依賴于摩擦的驅動，其公法線一定不能穿過驅動件或從動件的中心。忽略摩擦，且兩相互接觸物體間的力沿著法線作用時，當力的作用線沒有穿過從動件的轉動樞軸線時，從動件將被主動驅動。圖4-1B中的物體，接觸點在P，提供主動驅動。

任一直接接觸物體，其速率比的公式中唯一的變量就是圖4-1B中點f的位置。因此，保持勻速或恒定速率比的條件是公法線在一些固定點上通過中心線。盡管法線可能會轉動，但只要它在相同點通過中心線，速率比將會保持恒定。

對于大多數給定的物體形狀或輪廓，另一物體的，輪廓都能被構造出來，用于以勻速速率傳遞運動。這就是共軛輪廓。其本身就是存在能傳遞共軛運動的數學曲線；擺線和漸進線就是其中的兩種；用于齒輪輪齒中。擺線就是跟蹤空間中滾動輪邊緣的一點所形成的軌跡。輪齒的輪廓是跟蹤小圓邊緣的一點在大圓內外側滾動所形成的軌跡。漸開線就是處于大圓的內外側，漸開線就是跟蹤小圓邊緣一點沿大圓內外側滾動所形成的軌跡。漸開線也是跟蹤從圓柱體上展開的線上的一點所形成的軌跡。通過研究一對漸開線的接觸能很好地理解兩漸開線輪齒表面的相互作用方式。圖4-2中，由基圓1和基圓2產生的兩條漸開線通過點m、f和n想聯接，且應注意到由于基圓2比基圓1大，漸開線便有不同的形狀。

第五單元

連桿機構

連桿機構也許可以定義為實體物體或連桿的載體，其中每根桿件通過銷聯接（鉸鏈）或滑動接頭至少和其他兩個桿件相聯接。為了滿足這個定義，連桿機構必須形成一個無限的封閉的鏈或一系列封閉的鏈。很明顯，由很多桿聯接的鏈與只有一個桿相比，其性能是不同的。這在機械上就提出了一個非常重要的問題，那就是為傳遞運動而給定機構的適應性問題。其適應性取決于桿件和街頭的數量。

自由度，三桿機構（包括三桿聯接在一起的）很明顯是一個剛性框架；連桿之間不可能有相對運動，為了表達四桿機構中連桿的相對位置，只需知道任意兩桿間的夾角。（算上固定連桿OQ，圖5-1C所示機構有4個連桿，因此是四桿機構。）這個連桿機構有一個自由度。要確定五桿機構中連桿的相對位置需要兩個角度，也就是它有兩個自由度。

帶有一個自由度的連桿機構，其運動是有約束的。例如，連桿所有點在其它連桿上的軌跡是固定而又確定的。通過假定連桿上所求軌跡是固定的，并移動與約束相協調的連桿，軌跡是很容易得到的或很容易可視化觀察到。

四桿機構。當所受約束的連桿機構中的一個構件固定時，這個連桿機構將變成一個在機械中能夠完成有用的機械功能的機構，在銷連接的連桿機構中，輸入桿（主動桿）和輸出桿（從動桿）通常是以樞軸的連接方式連接到固定桿上的；這個連接桿（連接件）通常既不是輸入桿，也不是輸出桿。由于任意連桿都能固定。如果四種機構中，連桿都不等長，并且都有不同的輸入-輸出關系，那么就能得到四桿機構。這四種機構也就是所謂的基本連桿機構的轉換。

當圖5-1左邊中最短桿a固定時，桿b和桿d就能完成整圈的旋轉運動。這就是雙曲柄機構。若曲柄b以恒定的速度轉動，則曲柄d將以變化的速度作同向轉動。雙曲柄機構本身，或者和別機構聯接起來時，其曲柄都能提供有用的運動效果，圖中，曲柄b是主動桿，它以勻速率逆時針旋轉；曲柄d為從動件；三者都能同時完成整圈的旋轉運動。但當b轉過150°的角度是，從動桿d只能轉動50°的角度。這就是意味著從B運動到B’時，曲柄d將比b轉得慢，而從B’運動到B時，d比b轉得快。如果將同樣比例的曲柄d聯接到包裝機械的主軸上，例如聯接運動較慢的軸上，那它將會暫停運動或者停頓。這在必須慢速的地方將派上用場。

通過將最短桿a作為主動桿能得到四桿機構的第二種轉換。如圖5-1右所示，在桿a做整圈旋轉運動的同時；其相對的桿，可能在桿b，c，或桿d，卻只能在φ角的范圍內擺動。這稱為曲柄搖桿機構。它是產生帶有急回動作的擺動運動的有用裝置。產生急回運動的原因是：當桿a逆時針旋轉時，會帶動桿 c從B擺動到B’，其擺過角度為θ1，而桿c從B’擺動到B時，其擺過的角度為θ2。由于曲柄a的轉速是恒定的，且θ1大于θ2，因此搖桿從右擺動到左的時間將長于其它擺動途徑。只有當活動桿件沿一個方向移動，急回裝置快速將桿件送回初始位置時，機械才是做有用功。

圖5-1右所示的極端位置，曲柄a與連接桿b共線，且假定搖桿c為主動桿時，就必須提供方法使從動桿a通過死點。在用腳踏式操作的磨刀機上，腳踏板連接著桿c，磨刀機主軸連接著桿a，就是靠著磨刀機的角動量使桿通過死點。

在四桿機構的第三種轉換中，最短桿a為連接桿，其它的桿件只能擺動，這就是雙搖桿機構。

連桿機構的綜合，在連桿機構中，用圖形法和分析法很容易測定出桿件的位移，速度和加速度。設計或綜合連桿來滿足特定要求就難得多了。還沒有可用的方法來設計雙曲柄機構以滿足給定的輸入-輸出的關系譜。能做的就是調查一些選定的特定結構的性能特性。并挑選出其中最佳的

在曲柄搖桿機構中，設計者能控制搖桿的擺動角度，并在一定的程度上控制急回。而曲柄和要干的位移，速度和加速度卻無法關聯起來。

若四桿機構中的連桿總是以相同或相反的方向轉動，并且他們的轉動范圍遠小于180°，那么就有可能將曲柄轉動在3點，4點，5點或者甚至更多的位置關聯起來。圖形法和分析法都能建立這種關聯。

第六單元 飛輪

飛輪是一個連接到機械主軸上的重的輪子，它的目的是為了抵消和減輕在機械速度上由所提供的或所需要的動力的造成的速度不均勻性引起的任何波動。飛輪也被用來測試制動器和儲存可以在緊急情況下使用的能量，或者可以在快速釋放時提供大的力。

抵抗一個旋轉物體使其速度發生變化的辦法是改變它的慣性矩。這個性質取決于對旋轉軸的材料的處置上。慣性矩是與物體的每個構件的重量和它們到旋轉軸的距離的平方獲得的乘積成正比。普通幾何形狀物體的慣性矩可以在手冊中得到；對于非普通的形狀，它們可以由整體的積分或者通過經驗來確定。從慣性矩的性質可知，一個飛輪的材質在盡可能離旋轉軸遠的地方集中是最有效的。因此最好的飛輪有一個通過輪輻或圓盤連接到中心輪轂重的輪緣。

一個飛輪的運行情況完全取決于扭矩或作用在它身上的轉動力。如果一個順時針的扭矩作用在一個固定的飛輪一段時間，這個飛輪將獲得一個順時針角度方向的速度，它與平均扭矩乘以時間段的積成正比，與飛輪的慣性矩成反比。如果一個旋轉飛輪受到與它旋轉方向相同的一個扭矩作用，它的速度將提升；反之，速度將下降。飛輪的慣性矩越大，由一個給定的扭矩引起的速度變化將越小。如果沒有扭矩作用在飛輪上，它的速度將不會改變。

在一個往復式發動機的每個旋轉期間作用在曲柄軸上的扭矩都會變化。這種變化是由于在汽缸中的蒸汽或氣壓的不均勻性和連桿（將活塞壓力轉變為曲柄軸扭矩）與曲柄軸之間的變化的夾角造成的。當曲柄和連桿是共線的，這時將沒有扭矩傳遞給曲柄，每次旋轉這種情況會發生兩次。在發動機上飛輪的一個附帶的功能是帶領曲柄軸經過這些死點位置。

所有的旋轉機械都構件都具有慣性矩和像飛輪一樣都會對扭矩變化作出反應。這些構件啟動、暫?；蛩俣茸兓枰呐ぞ乇环Q之為慣性扭矩或慣性載荷。慣性載荷存在于所有機械中，當機械啟動時它們的存在尤其明顯。

飛輪在間歇地傳遞機械功的機械上是特別有用的。例如，在沖床上，在活塞的下行沖程期間沖壓或成型金屬盤所需的大的力才會發生。在下行沖程的剩余時間，整個上行沖程和沖程之間的時段，機器是空轉的，來自驅動馬達的所需的動力是很低的。使用一個具有傳遞足夠大的扭矩去創造沖孔成型所需的大的力的驅動馬達是不經濟的。飛輪作用于儲存在機器空轉時由低動力馬達造成的能量和在下行沖程做工部分釋放部分能量。

在1880年代，一個快速旋轉的飛輪被用作魚雷推動系統的動力源；據報道，在450米的距離將獲得24海里/時的速度。在飛機上，直徑25厘米，轉速52000轉/分鐘的飛輪有足夠的能量去升起和降下起落架。這個飛輪儲能系統重90千克，低于完成相同功能的液壓系統。在公交運輸方面的一個近來（1970年）的應用是在無軌電車上使用飛輪的提議。新型的高密度的鋼輪，重300千克，轉速為每分鐘20000轉，它將允許電車離開電線行駛在臨近十公里的區域內。在飛輪上獲得高密度儲能能力的關鍵在于由材料可以帶動的旋轉引起的離心應力的大小。相同的材料，平的圓盤可以比輪緣形的輪子多儲能百分之50，而錐形的等壓力盤可以比輪緣形的輪子多儲能百分之100。

第八單元 材料的熱處理

熱處理是在固態下加熱和冷卻材料來改變它的的物理性質的工藝。根據所使用的工序，鋼可以被硬化來抵抗切割運動和磨損，或者它可以被軟化來進行進一步加工。結合適當的熱處理，可以消除內部應力，細化晶粒，增加韌性，或生產一個韌性的內部和硬的表面的材料。直到熱處理之前，在機械車間制造的大部分產物只有很少的價值或沒有價值。熱處理不僅可以用于鋼上面，也可以用在許多非鐵金屬上面，例如鋁，銅和黃銅。鋼熱處理的工序包括硬化淬火，回火，退火和表面淬火。

在許多人處理工藝上，加熱的速度是重要的。熱度以一定的速率從鋼的外部傳導到內部。如果鋼加熱太快，外部將會比內部更熱，不會得到均勻的結構。如果工件在形狀上是不規則的，為了消除變形和裂紋，緩慢的加熱速度是更加必要的。工件越重，為了達到均勻的結果，加熱時間必須更久。盡管已經達到了正確的溫度，工件也應該保持在這個溫度相當一段時間來使它最厚的截面達到相同的溫度。

1硬化

硬化是一個加熱和冷卻的過程來增加它的硬度和拉伸強度，降低延展性，和得到一個良好的晶粒結構。這工序包括在溫度的臨界點加熱金屬，隨后快速冷卻。隨著金屬被加熱，鐵和碳之間發生物理和化學的改變。這個臨界點或臨界溫度是鋼具有最理想特性的點。當鋼達到在1400到1600華氏度間的某個溫度，如果它被快速冷卻，這個變化對制出硬，又強的材料是理想的。如果金屬緩慢冷卻，它將會變回原本的狀態。通過把熱的金屬投入水，油或鹽水中（淬火），可以得到所想要的特性。金屬對比之前是非常強和硬的和有更少的延展性。

2回火

已經通過快速淬火硬化的鋼是脆的和不適合于大部分用途。通過回火，硬度和脆性將減少到耐用條件所需要的點。隨著這些性質減少，鋼的抗拉強度也會減小，而在延展性和韌性會增加。這個工藝包括了淬硬鋼再加熱到低于臨界范圍的某個溫度，隨后以任何速度冷卻。雖然這個過程軟化了金屬，但它完全不同于退火，在這個過程中回火有助于對物理性質的精細控制，和在大部分過程中，回火不會把金屬軟化到退火將達到的程度。最后從硬化金屬完全回火所得到的結構被稱為回火馬氏體。

因為硬化金屬的主要成分馬氏體的不穩定性，所以回火是合理的。從300到400華氏度的低溫不會造成硬度降低，它主要用于消除內部應變。隨著回火溫度的增高，馬氏體的分解將以更快的速度發生，和在大約600華氏度，變成被稱為回火馬氏體的結構是非常快的。

回火工藝可以被描述成沉淀和結塊，或滲碳體聚結的工藝。大量滲碳體的沉淀是在600華氏度，這會產生硬度降低。溫度升高會造成碳化物的聚結，而硬度會繼續降低。

3退火

退火的主要目的是軟化硬的鋼以致使它可以被機加工和冷加工。通常這是通過加熱金屬到稍稍在形成奧氏體的臨界溫度之上，并保持這個溫度直到工件的溫度處處相同，和那時以一個緩慢的可控速度冷卻以致使工件的表面溫度和中心溫度近似相等來完成的。這個過程被稱為完全退火，因為它消除了之前結構的所有的痕跡，提純了結晶結構，和軟化了金屬。退火也消除了以前在金屬產生的內部應力。

當硬化的金屬二次加熱到臨界范圍之上，組織將變回奧氏體，和緩慢冷卻，那時將提供足夠的時間完成奧氏體到更軟的結構的轉變。對于亞共析鋼，這些結構是珠光體和鐵素體。通過參考平衡態圖標，可以注意到過共析鋼退火溫度是更低的，稍稍在A線之上。沒有理由去加熱到A線之上，因為在這個點硬的組織滲碳體開始析出。通過加熱到更低的臨界范圍之上和緩慢冷卻，所有的馬氏體會轉變成珠光體。在鋼里面任何自由的滲碳體都不收這些處理的影響。

第九單元 材料的選擇與機械零件的強度

1材料的選擇

這些年來，工程材料的選擇已經顯得非常重要。此外，選擇過程應該是一個對材料的連續不斷的重新評價過程。新材料不斷出現，而一些原有的材料的可以被利用的數量可能會減少。環境污染，材料的回收利用.工人的健康及安全等方面的關心經常會對材料選擇附加新的限制條件。為了減輕重量或者節約能源，可能會要求使用不同的材料，來自國內和國際的競爭.對產品維修方便性要求的提高和顧客的反饋等方面的壓力。此外，材料與材料加工之間的相互依賴關系已經被人們認識得更清楚，新的加工方法的出現通常會促使人們對被加工材料進行重新評價。因此，為了能在合理的成本和確保質量的前提下獲得滿意的結果，設計工程師和制造工程師都必須認真仔細地選擇，確定和使用材料。

制造任何產品的第一步工作都是設計，設計通?？梢苑譃閹讉€明確的階段，（a）總體設計b)功能設計c)生產設計。在總體設計階段，設計者著重考慮產品應該具有的功能。通常要設想和考慮幾個方案，然后決定這種想法是否可行；如果可行，則應該對其中一個或幾個方案作進一步的改進，在此階段，關于材料選擇唯一要考慮的問題是：是否有性能符合要求的材料可供選用，如果沒有的話，是否有較大的把握在成本和時間都允許的限度內研制出一種新材料。

在功能設計或工程設計階段，要做出一個切實可行的設計，在這個階段要繪制出和相當完整的圖紙，選擇并確定各種零件的材料，通常要制造出樣機或者實物模型，并對其進行試驗，評價產品的功能，可靠性，外觀和適用性等，雖然這種試驗可能會表明，在產品進入到生產階段之間，應該更換某些材料，但是，絕對不能將這一點作為不認真選擇材料的借口，應該結合產品的功能，認真仔細地考慮產品外觀，成本和可靠性。一個很有成就的公司在制造所有樣機時，所選用的材料應該和其在生產中使用的材料相同，并盡可能使用同樣的制造技術，這樣做對公司是很有的。功能完備的樣機如果不能根據預期的銷售量經濟地制造出來，或者是樣機與正式生產的裝置在質量和可靠性方面有很大不同，則這種樣機就沒有多大的價值。設計工程師最好能在這一階段全部完成材料的分析，選擇和和確定工作，而不是將其留到生產設計階段去做。因為，在生產設計階段材料的更換是由其他人進行的，這些人對產品的所有功能的了解可能不如設計工程師。

在生產設計階段中，與材料有關的主要問題是應該把材料完全確定下來，使它與現有的設備相一對一，能夠利用現有設備經濟地進行加工，材料的數量能夠比較容易地保證供應。

在制造過程中，不可避免地會出現對使用中的材料作一些更改的情況，經驗表明，可以采用某些理家材料作為替代品。然而，在大多數情況下，在進行生產以后改換材料要比在開始生產前改換材料所花費的代價要高在生產設計階段做好材料選擇工作，可以避免大多數的這種材料更換情況，在生產制造開始后出現了可供使用的新材料的。當然，這些新核燃料可能降低成本，改進產品性能。但是，必須對新材料進行認真的平價，以倚其所有性能都被人們所了解。應當時刻牢記，新材料的性能和可靠性很少能像現有材料那樣為人們所了解大部分的產品失效和產品責任事故案件是由于在選用新材料作為替代材料之前，沒有真正了解它們的長期使用性能而引起的。

產品的責任訴訟迫使設計人員和公司在選擇材料時，采用最好的程序，在材料選擇過程中，五個最覺的問題為：（A）不了解或者未能利用關于材料應用方面的最新和最好的信息資料（B）未能和考慮產品可以的合理用途，如有可能，設計人員還應進一步和考慮由于產品使用方法不當造成的后果。在近年來的許多產品責任訴訟案件中，由于錯誤地使用產品而受到傷害的控告生產大家，并且贏得判決（C）所使用材料的數據不全或者有些數據不確定，尤其是當具長期性能數據是如此的時候（D）質量控制方法不適當和經驗證明由一些完全 不稱職的人員選擇材料。

通過對上違一個問題的分析，可以得出這些問題是沒有充分理由存在的結論，對這些問題的分析和研究以給避免這些問題的指明方向。以往采用最好的材料選擇辦法也不能避免發生產品責任訴訟，設計人員工業界按照適當的程序進行最佳選擇，可以大減少訴訟的數量。

因為所生產的壓痕尺寸的函數，這表明由于硬度是非破壞性試驗，而且不需要專門的，因而硬度是一個容易測量的性能，通?？梢灾苯釉趯嶋H的機械零件上進行硬度試驗。

第十單元

車床及其他機床

車床

1.車床用于旋轉工件，并朝著生成所需要加工的表面方向進給切削刀具。2.最常見的車床形式是圖10-1a中以圖解方式顯示的六角車床，它由一個支撐著床頭箱，拖板和六角刀架的水平床身組成，工件夾在卡盤和夾頭中，或者安裝在機床主軸端部的花盤上。3.工件的旋轉由一臺電機通過一個齒輪系驅動主軸提供。4.切削刀具安裝在橫向滑板及六角刀架上，在橫向滑板上的刀具在平行于工件旋轉軸線方向或在工件旋轉軸線的法線方向驅動或給進。六角刀架可以通過分度頭將各種刀具定位并可以沿車床的床身方向驅動或給進。

5.現代六角車床由計算機控制所有工件和刀具運動，這些車床稱為計算機數字控制(CNC)車床，而且刀具或橫向滑板可以在水平面上的任一方向進給以使工件上產生所需的廓形。6.圖10-1b說明的是通過工件旋轉以及托板沿車床床身運動所產生的柱面，這一工序稱為外圓車削。

7.車床設定的進給運動也就是工件每轉一圈刀具移動的距離，機床的進給量f的定義是：刀具或工件每一行程或每轉一圈，刀具相對于工件在進給運動的方向的位移，這樣，為了車削長度為Lw的柱面，工件的轉數是Lw/f,則加工時間Tm由下式給出的Tm=Lw/(fnw)，式中nw是工件的旋轉速度。

8.在此應當強調t，是刀具沿工件走一次（一次切削）的時間，但是，這一次通過并不意味著加工工序的完成，如果首次切削用于以高進給來去除大量材料（粗切），在操作過程中產生的力將有可能引起機床結構的明顯撓曲，引起的精度損失可能需要以小進給量進一步加工（精切），使工件直徑在規定的界限內并提供光滑的加工表面。由于這些原因，在粗切時常被加工成稍大一點的尺寸，留下少量材料在隨后的精加工中去除。立式鏜床

9.水平主軸的車床不適于車削沉重的大直徑工件，否則機床主軸的軸線將不得不升高到機床操作工夠不到固定刀具或固定工件的裝置的高度，此外，在垂直的花盤上安裝零件或在頂尖之間支撐零件會有困難，因此使用了一種與車窗相同的工作原理，但具有垂直軸線的機床并稱為立式鏜床（圖10-2），這種機床像車床那樣旋轉工作并向刀具施加連續的,線性的進給運動。

10.（立式鏜床）使用單刃刀具，而且進行的作業一般限于車削，端面車削和鏜削。

11.便于定位大型工件的水平工件臺由一個帶有徑向T型槽的，起夾持作用的旋轉工作臺構成

臥式鏜床

12,這里介紹的另一種實用單刃刀具并具有旋轉主運動的機床是臥式鏜床（圖10-3），這種機床主要用于沉重的圓柱形工件，在這種工件內有一個待加工的內圓柱形表面，一般講，在描述機床時，使用臥式或立式來講。兩個詞指的是提供主運動的機床軸（主軸）的姿態，可見，在臥式鏜床中，主軸是水平的。

13,此類機床的主要特征是，工件在加工過程中保持靜止，所有造型運動都施加在刀具上。最常見的加工工序是鏜削，如圖所示，鏜削是通過旋轉刀具來實現的，刀具安裝在與主軸相連接的鏜桿上，然后沿旋轉線進給主軸，鏜桿和刀具的進給是用于移動工件的機床運動只是用來給工件定位，在進行加工時一般不使用，端面車削工序可以通過使用專門刀具架（圖10-4），在其旋轉時徑向進給刀具來實現。

此外先前推導的鏜削和端車加工時間和金屬切削率的公式仍將適用。刨床

14,刨床適用于在非常大的部件上加工平面，在這種機床（圖10-5）上，線性運動作用在工件上，二刀具則垂直于該運動的方向進給，主運動通常利用變速馬達通過齒條與齒輪傳動來實現，而且進給運動是斷續的工序用提供的T型槽固定在機床的工作臺上，加工時間tm和金屬切削率zw可以按下面公式估算：tm=bw/(fnr),式中bw是待加工面得寬度。Nr是切削行程的頻率，f是進給量，金屬切削率zw由下式給出zw=fapv，式中v是切削速度，ap是切口深度（去除材料層的深度）

第十一單元基本的加工工序——切削、鏜削、和磨削

基本的加工工序

機床是從早期的埃及人的腳踏動力車床和約翰。威爾金森的鏜床發展而來，它們用于為工件和刀具兩者提供堅固的支撐并且可以精確控制它們的相對位置和相對速度。基本上講，在金屬切削中一個磨尖的楔形工具以緊湊變形的切削形式從有韌性的工件表面去除一條很窄的金屬。切削是一種廢棄的產品，與其他工件相比它相當短但是比未切削的部分厚度有相對的增加。機器表面的幾何形狀取決于刀具的形狀和加工操作過程中刀具的路徑。

大多數加工工序產出不同幾何形狀的部件。如果一個粗糙的圓柱形工件繞中心軸旋轉而且刀具穿破工件表面并與旋轉中心平行的方向前幾，就會產生一個旋轉面，這道工序叫做車削。如果以類似的方式加工一根空心管的內部，則這道工序叫鏜削。制造一個直徑均勻變化的錐形外表面叫做錐體車削。短的錐面或柱面也可以仿形車削。如果刀具尖端以一條半徑可變的路徑前進，就可以制造出像保齡球桿那種仿形表面。如果工件足夠短（約1英寸）而且支撐具有足夠的剛性，仿形表面可以通過進給一個垂直于旋轉軸的仿形刀具來制造。

常常需要的是平坦的或平的表面。它們可以通過徑向車削或端面車削來完成，期中刀具尖端沿垂直于旋轉軸的方向運動。在其他情況下，更方便的是固定工件不動；以一系列直線式切削的方式使刀具橫過工件作往復運動，在每次切削行程前具有一定橫向進給量。這一工序叫做刨削，是在牛頭刨床上進行的。對于大一些的工件，很容易保持刀具固定不動，而像龍門刨削那樣在其廈門拉動工件。仿形面可以通過使用仿形刀具來制造。

在每次往復時進給刀具。也可以使用多刃刀具。鉆削使用兩刃刀具，孔深可達鉆頭直徑的5~10倍。不管是鉆頭轉動還是工件旋轉，切削刃與工件間的相對運動是一個重要的因素。在銑削操作中，有許多切削刃的旋轉銑刀與工件相接合，這種工件相對銑刀運動緩慢。根據銑刀的幾何形狀和進給的方式，可以加工出平面和仿形面?？梢允褂盟交虼怪毙D軸，工件可以沿三個坐標方向中的任意一個進給。

基本的機床

機床用于以切削的形式從韌性材料上去除金屬來加工特殊幾何形狀和精密尺寸的部件。切屑是廢品，其變化形狀從像鋼這樣的韌性材料的長的連續帶狀到鑄鐵形成的易于處理、徹底斷掉的切屑，就處理的觀點來講，不想要長的連續帶狀屑。機床完成5種基本的金屬切削工藝：車削，刨削，鉆削，銑削和磨削。其他所有金屬切削工藝都是這5種基本工藝的變形。因此，僅有4種使用專用可控幾何形狀的刀具的基本機床：

1、車床

2、刨床

3、鉆床

4、磨床。例如：鏜削是內部車削：鉸削、攻絲和平底锪孔是修改已鉆好的孔，與鉆削有關；滾齒與切齒基本上是銑削作業；弓鋸削和拉削是刨削和研磨的一種形式；而研磨、超精加工、拋光和磨光則是磨削和研磨切削加工作業的各種變化形式。磨削工藝形成碎屑，但是磨粒的幾何形狀不可控制。

不同加工工藝切削材料的量和速度可能很大，如在大型車削作業或極小，如研磨或超精加工作業，只有表面高出的點被去除。

機床完成3種主要功能：

1、剛性支撐工件或工件的夾具以及切削刀具；

2、提供工件與切削工具間的相對 運動；

3、提供了一定范圍的進給和速度，通常每種情況有4~32種選擇。加工中的速度和進給

切削速度、進給和深度是經濟加工的3個主要變量，其他變量還有工件和刀具材料，冷卻劑以及切削刀具的幾何形狀，金屬切削的速率和加工所需的功率就取決于這些變量。

切削深度，進給和切削速率是在任何金屬切削作業中都必須建立的機器設置，它們都會影響切削力，功率和對金屬切削的速率。切削的深度是唱針進入唱片的量或者是槽的深度。切削速度由任意時刻唱片表面和對于拾音器臂內的唱針的速度來表示進給由唱針每圈徑向向內的前進量或者把兩個相鄰槽的位置間來表示可以通過把它們與留聲機的唱針和唱片相比較給出其定義。

第十二單元 計算機輔助設計

好的工程設計需要保證一個部件或機構正確的運轉和持續相當長的一段時間。此外，在設計過程的功能性因素包含重量，強度，熱性能，運動學和動力學。

第十五單元

柔性制造、一、柔性制造的定義

制造的演變用圖表示為一個連續統一體，如圖15-1所示。如此圖顯示的那樣，制造的過程和系統處在把手工操作到最后實現全盟的集成制造的過度狀態。計算機集成制造的前一步叫做柔性制造。

柔性在現代制造環境中是一個重要的特征。它意味著一個制造系統是用途多且適應性強，同時又能進行產量相對較大的制造。柔性制造系統是多用途的，這是因為它能制造多種多樣的部件。它適應性強，因為它能很快地加以改變來制造完全不同的另一種部件。這種柔性在競爭激烈的國際市場上可能成敗有別。

這是一個平衡的問題。獨立的計算機數字控制（nc）機床有著高度的柔性，但是只能處理批量相對較小的制造。正相反，系列連鎖生產線能進行批量較大的制造，但都不很靈活。柔性制造試圖運用工業技術在靈活的與制造運行間達到最佳的平衡。這些工業技術包括自動化的材料、處理，成組技術及計算機和分布數字控制。

柔性制造系統（FMS）是一個獨立的機床或一組機床服務于一個自動材料處理系統。它是由計算機控制的而且有對刀具處理的能力。由于他有刀具處理能力并受計算機控制，這樣的系統可以不斷的重新配置來制造更加多樣的部件，這就是它被稱作柔性制造系統的原因。

一個制造系統要成為柔性制造系統必須具備的要素有：

1、計算機控制

2、自動處理材料能力

3、刀具處理能力

柔性制造向全面集成化制造的目標邁進了重要的一部。它實現了自動制造過程的集成化。在柔性制造中，自動化的制造機器（如車床、銑床、鉆床）和自動化材料處理系統之間，通過計算機網絡進行即時的溝通。這是小規模的集成，圖15-2是柔性制造系統的一個樣例。

二、柔性制造的概況

通過綜合幾個自動化的制造概念，柔性制造系統向全面集成化的目標邁出了重要的一步，這些觀念是：

1、獨立機床的計算機數字控制

2、制造系統的分布式數字控制

3、自動化的材料處理系統

4、成組技術，零件族

當這些自動化工藝，機器和觀念合成到一個集成的系統時，就產生柔性制造系統。在柔性制造系統中，和計算機起了重要作用，當然大的勞動量比手工操作的制造系統要小得很多。然而，人仍然在柔性制造系統的操作中起了至關重要的作用，人的任務包括幾個方面：

1、設備故檢、維護和修理

2、刀具的變換和設置

3、安裝和拆卸系統

4、數據輸入

5、部件程序的變換

6、程序的開發

柔性制造系統設備像所有制造設備一樣，必須有人監管以免出現失常、機器程序錯誤，以及故障。當發現問題時檢修人員必須確定問題的根源，然后給出正確的措施，人還要采取指定的措施來修理運行不正常的機器。甚至當所有系統正常運轉時，定期的維護也是必要的。

操作人員還要根據需要設置機床，換刀具，以及重新配置系統。柔性制造系統的刀具處理能力消弱了，但并沒有消除，在刀具變換和設置上仍需要人力。在裝卸柔性制造系統時也是這樣，一旦原材料被送到自動化材料處理系統上，它就會以規定的方式，在系統中移動。然而，初裝到材料處理系統仍然是由人員完成的，成品的拆卸也是同樣。

與計算機的交流仍需要人力完成，人開發零件程序，通過計算機控制柔性制造系統。當重新配置FMS制造另一種類型零件時，他們還在必要的時候變換程序。人在柔性制造系統中勞動力密集型的成分越來越少，但仍然是很重要的。

柔性制造系統中的各層控制都是由計算機來完成的。在柔性制造系統中獨立的機床是由CNC來控制點。整個的系統是由DNC來控制的。自動化的材料處理系統是計算機來控制的，其他的功能如數據收集、系統監控、刀具控制、運輸控制也是計算機控制的，人機交互是柔性制造系統中的關鍵。

二、柔性制造的歷史發展

柔性制造產生于20世紀60年代中期，當時英國莫林斯有限公司開發了24號系統。24號系統是一個真正的FMS。然而，它從一開始就注定是失敗的，因為自動化、集成化和計算機控制技術還沒有發展到能夠恰好支持這一系統的程度。第一個FMS是超前的開發。因此，最終因不能工作而被放棄。

在20世紀60年代和70年代的其余時間里，柔性制造仍然是一個學術觀念。然而，隨著復雜計算機控制技術在20世紀70年代末和80年代初的出現，柔性制造便成為可能。在美國最初的主要用戶是汽車、卡車和拖拉機制造商。

四、柔性制造的理由 在制造中，生產率和柔性之間經常存在協調一致的問題。在該領域的一端是具有高生產率卻低柔性的連續生產線，在該領域的另一端是能提供最大柔性的獨立的計算機數字控制的機床，但它只能進行低生產率的制造。柔性制造處在此連續統一體的中間。在制造中總是需要一個系統，這個系統比單個機床能制造更大批量且用于更多制作過程，但仍保持其柔性。

連續生產線能以高生產率制造大量的零件。這條生產線需要大量的準備工作，但卻能制造出大量的相同的零件。它的主要缺點是即使一個部件在設計上有小的改變都能造成整個生產線的停產和建構改變。這是一個致命的弱點，因為這意味著沒有高成本，耗時停工和變化連鎖生產線結構是不能制造出不同的零件的，即使是來自同一個零件族。

傳統上計算機數字控制機床是用來制造少量在設計上稍有不同的零件。這種機床很適合這一用途。因為它們能迅速地改變程序來適應設計上小的或者更大的改變。然而，作為獨立的機床它們不能大量地或高生產率地制造零件。

柔性制造系統比獨立的計算機數控機床具有更大的生產能力和更高的生產率。它們在柔性方面比不上計算機數字控制機床，但它們卻相差不多。柔性制造的中間性能的特殊意義在于大多數制造要求中等量的生產率來制造中等及的產品。同時有足夠的柔性以快速改變結構來制造另一個零件或產品。柔性制造填補了制造中長期存在的空白。

柔性制造以其基本能力給制造者提供了許多有點：

1、在一個零件族內具有柔性

2、隨意進給零件

3、同時制造不同的零件

第三篇：機械電子專業英語翻譯

Quality Control Fundamentals質量控制基本原理 Quality質量

Quality has become one of the most important consumer decision factors in the selection among competing products and services.The phenomenon is widespread, regardless of whether the consumer is an individual, an industrial organization, a retail store, a bank or financial institution, or a military defense program.Consequently, understanding and

improving quality are key factors leading to business success, growth, and enhanced competitiveness.There is a substantial return on investment from improved quality and from successfully employing quality as an integral part of overall business strategy.質量是消費者在激烈的產品和服務競爭中進行選擇的一個重要因素.不管這個消費者是個人、產業組織、零售店或防務工程,這個想象是普遍存在的.因此,關注并提升質量是取得成功、發展并強化競爭力的關鍵因素.投資質量的提升并把質量作為經營策略的主要部分將會得到極大地回報.We may define quality in many ways.Most people have a conceptual understanding of quality as relating to one or more desirable characteristics that a product or service should possess.Although this conceptual understanding is certainly a useful starting point, we will give a more precise and useful definition.我們對質量有很多種定義.許多人在觀念上把質量理解為產品或服務擁有一個或更多滿意的性能.盡管這種概念性理解是有效地,我們將給出更精確、有效地定義.Quality----characteristic or property consisting of several well-defined technical and aesthetic, hence subjective, considerations;conformance to design(customer)requirement.質量-特性或性能中包含幾種明確定義的技術的美學的,因此主觀考慮；滿足設計（顧客）需求.Quality control------detecting poor quality(nonconformance)in manufactured products and taking corrective action to eliminate it.質量控制-檢測在工業產品中檢測不合格的質量（不合格品）并采取糾正措施去避免.The traditional definition of quality is based on the viewpoint that products and services must meet the requirement of those who use them.Therefore, Quality means fitness for use.傳統的質量定義是產品或服務必須滿足使用者的需求.因此,質量就是適用度

There are two general aspects of fitness for use: quality of design and quality of conformance.適用度一般有兩個方面:設計質量和一致性的質量。

Quality by design intent refers to the various grades or levels of quality that are intentionally determined by design.All goods and services are produced in various grades or levels of quality.These variations in grades or levels of quality are intentional, and, consequently, the appropriate technical term is quality of design.設計意圖的質量指的是設計中故意設計的各種等級或質量等級。所有的商品和服務都是在不同的等級或質量等級中產生的。這些變化的等級或質量水平是故意的，因此，適當的技術術語稱之為設計質量。

Quality of conformance refers to how well the product conforms to specifications required by design.產品質量的一致性是指如何符合規范設計的要求。

Quality of conformance is influenced by a number of factors, including the choice of manufacturing processes, the training and supervision of the workforce, the types of process controls, tests, and inspection activities that are employed, the extent to which these procedures are followed, and the motivation of the workforce to achieve quality.一致性質量受到很多因素的影響,包括生產流程的選擇、員工的培訓和監督，所采用的過程控制,測試,和檢查活動的類型,這些程序被遵循的程度 ,激勵員工來實現質量。

Unfortunately, this definition has become associated more with the conformance aspect of quality than with design.This is in part due to the lack of formal education most designers and engineers receive in quality engineering methodology.This also leads to much less focus on the customer and more of a ―conformance-to-specifications‖ approach to quality, regardless of whether the product, even when produced to standards, was actually ―fit-foruse‖ by the customer.Also, there is still a widespread belief that quality is a problem that can be dealt with solely in manufacturing, or that the only way quality can be improved is by ―gold-plating‖ the product.不幸的是,相對于設計，這個定義更多的關于質量的一致性。這部分是由于大多數設計師和工程師缺乏質量工程方法的正規教育。這也導致更少地關注客戶和更多關注質量與規格一致, 無論產品，即使生產標準，實際上是“適合使用”的客戶。同時,普遍仍認為,在生產制造中質量問題完全可以解決, 或者唯一的可以提高質的方式是給產品“鍍金”。

We prefer a modern definition of quality: Quality is inversely proportional to variability.Note that this definition implies that if variability in the important characteristics of a product decreases, the quality of the product increases.As an example of the operational effectiveness of this definition, a few years ago, one of the automobile companies in the United States performed a comparative study of a transmission that was manufactured in a domestic plant and by a Japanese supplier.我們傾向于質量的現代定義:質量與變化成反比。請注意,這個定義意味著如果產品的重要特征的變化減少,產品的質量就會提高。舉一個這個定義的操作效益的例子,幾年前, 美國的一個汽車公司進行了一個在國內工廠制造過程的傳輸和由日本供應商制造過程的傳輸的比較研究。

An analysis of warranty claims and repair costs indicated that there was a striking difference between the two sources of production, with the Japanese-produced transmission having much lower costs, as shown in Fig.5.1.As part of the study to discover the cause of this difference in cost and performance, the company selected random samples of transmissions from each plant, disassembled them, and measured several critical quality characteristics.保修索賠和維修費用的分析表明，兩者的生產有著顯著的區別，如圖5.1所示，日本制造的運輸成本很低。這項研究的一部分是發現成本和表現中這種差異的原因，公司從每個工廠隨機選擇抽樣，拆卸樣本，并測量了幾個關鍵的質量特性。

Figure 5.2 is generally representative of the results of this study.Note that the distribution of the critical characteristics for the transmissions manufactured in the United States takes up about 75% of the width of the specifications, implying that very few nonconforming units would be produced.In fact, the plant was producing at a quality level that was quite good, based on the generally accepted view of quality within the company.However, the Japanese plant produced transmissions for which the same critical characteristics take up only about 25% of the specification band.As a result, there is considerably less variability in the critical quality characteristics of the Japanese-built transmissions in comparison to those built in the United States.圖5.2通常是這項研究的結果的代表。注意的是美國生產傳輸的臨界特征的分布 占寬度規格的75%左右,這意味著不相容的產品很少。事實上, 根據公司內部的質量標準，工廠生產的質量水平很好,然而,日本工廠的生產傳輸的相同的臨界特征規范只占用約25%的規格帶。因此,日本建立的生產傳輸中的關鍵質量特征的變化要比美國的少很多。

There are two obvious questions here: Why did the Japanese do this? How did they do this? The answer to the ―why‖ question is obvious from examination of Fig.5.1.Reduced variability has directly translated into lower costs。Furthermore, the Japanese-built transmissions shifted gears more smoothly, ran more quietly, and were generally perceived by the customer as superior to those built domestically.Fewer repairs and warranty claims means less rework and the reduction of wasted time, effort, and money.Thus, quality truly is inversely proportional to variability.How did the Japanese do this? The answer lies in the systematic and effective use of the methods described in this text.這里有兩個明顯的問題:為什么日本人這樣做呢?他們是如何做到這一點呢? 再看圖5.1，“為什么”的問題的答案是顯而易見的。減少的變化直接轉化為低成本。此外,日本造的變速齒輪更順暢,更安靜，客戶通常認為日本的變速齒輪要比國內的好。更少的維修和保修索賠意味著很少的返工,節約時間 ,精力,和金錢。因此,質量真的是與變化成反比。日本人是怎么做的呢?答案就在于系統和有效地使用本文中描述的方法。

Dimensions of Quality質量維度 The quality of a product can be described and evaluated in several ways.It is often very important to differentiate these different dimensions of quality.Garvin provides an excellent discussion of eight components or dimensions of quality.We summarize his key points concerning these dimensions of quality as follows: 一個產品的質量可以用幾種方法來描述和評價。區分這些不同維度的質量往往是很重要的。加文 對于質量的八種要素做了一個很好的討論。我們總結了他的關鍵點，這些尺寸的質量如下：

Performance –product does intended job

表現—產品滿足特定功能 Reliability—product is available 可靠性----產品是可用的

Durability—product lasts for a reasonable time 持久性---產品能使用一個合理的時間 Serviceability—product is easy to repair/service

維護性---產品維修維護方便

Aesthetics—product has acceptable/appealing appearance

美觀---產品具有可接受或吸引人的外觀

Features—product has capabilities beyond basic performance 功能性---產品具有超越基本功能的功能

Perceived Quality—product & company have good reputation;measured by customer loyalty 感知質量—產品和公司在消費者中具有良好的聲譽。

Conformance to Standards—product made consistent with designer intent(and consistent with industry & national standards)標準一致---制造的產品符合設計師的意圖（并符合行業和國家標準）。

Quality Improvement質量的提升 Quality improvement is the reduction of variability in processes and products.Excessive variability in process performance often results in waste.For example, consider the wasted money, time, and effort that is associated with the repairs represented in Figure 5.1.Therefore, an alternate and frequently very useful definition is that quality improvement is the reduction of waste.質量改進是減少過程和產品中的變化。過程性能的過度變化往往導致浪費。例如，圖5.1所反映的維修中浪費的金錢，時間和精力。因此，一個替代的，通常是非常有用的定義是，質量改進是減少浪費。

Implementing quality improvement: management must 實施質量改進：管理

Evaluate dimensions of quality as they pertain to their business objectives(assuming the objectives are defined);評估質量維度與他們的業務目標（假設定義了目標）； Think strategically about quality;戰略性地考慮質量；

Recognize critical role of suppliers in quality management strategies;認識到供應商在質量管理戰略中的重要作用；

Recognize that everyone in the organization is responsible for quality;認識到組織中的每個人都對質量富有責任；

Recognize that statistical quality control techniques communicate both problems & solution;認識到統計質量控制技術，溝通問題和解決方案；

Implement effective quality improvement programs tailored to their business;針對他們的業務實施有效的質量改進方案；

Total quality management;全面質量管理；

Quality improvement benefits—business growth;enhanced competition;cost reduction;reduced product liability;improved productivity.質量改進的效益----業務增長；增強競爭；降低成本；減少產品債務；提高生產率。

Quality Engineering Terminology質量工程術語

Every product possesses a number of elements that jointly describe what the user or consumer thinks of as quality.These parameters are often called quality characteristics.Quality characteristics –-Physical;Sensory;Time Orientation;can be attributes or variable.每個產品都有許多描述用戶或消費者心目中的質量的要素。這些參數通常被稱為質量特性。

品質特性–身體；感官；時間方向；可以是屬性或變量。

Quality engineering—the set of operational, managerial and engineering activities used to ensure that quality characteristics of a product are at nominal or the required levels.質量工程---一套確保產品的質量特性是在名義或所需的水平操作，管理和工程活動。

Statistical methods—applied to measurements for product’s quality characteristics, they are usually the result of the engineering design process for the product.統計方法---用于測量產品的質量特性,通常是產品的工程設計過程的結果。Quality measurement---compare measured value to nominal or target value for characteristic;values bounded by allowable limits, namely, upper specification limit(USL)and low specification limit(LSL)(determined by design engineer);values outside limits are considered to be nonconforming, hence, product is defective.質量測量——將質量的測量值與真值相比較，特征值被范圍所限制，即規范上限(USL)和規范下極限(LSL)(由設計工程師決定);特征值外部限制被認為是不一致的,因此,產品是有缺陷的。

Concurrent engineering---multi-disciplinary, team-based approach to design(early in design process).并行工程---多學科，以團隊為基礎的設計方法（多在早期的設計過程）。

History of Quality Methodology質量方法學史

Quality always has been an integral part of virtually all products and services.However, our awareness of its importance and the introduction of formal methods for quality control and improvement have been an evolutionary development.Table 5.1 presents a timeline of some the important milestones in this evolutionary process.質量幾乎一直是所有產品和服務的一個組成部分。然而，我們意識到它的重要性，并介紹了正式的質量控制和改進的方法，一直是一個進化的發展。表5.1給出了一些在這個進化過程中的重要里程碑的時間線。

A Timeline of Quality Methods質量測量方法的時間線

1700—1900 Quality was largely determined by the efforts of an individual craftsman.Eli Whitney introduces standardized, interchangeable parts to simplify assembly.質量在很大程度上取決于個人的努力。伊萊·惠特尼介紹標準化，可互換的零件以簡化裝配。1875 Frederick W.Taylor introduces principles of Scientific Management；division of labor &work standards;improved productivity.1875年弗雷德里克·W·泰勒 介紹了科學管理的原則；勞動分工和勞動標準；提高生產率。

1900–1930 Henry Ford—the assembly line—further refinement of work methods to improve productivity and quality;Ford developed mistake-proof assembly concepts, self-checking, and in-process inspection.亨利福特的裝配線進一步細化工作方法以提高生產率和質量；福特開發的防誤裝配的概念，自我檢查和中間驗收，1924 Walter.A.Shewhart introduces the control chart concept in a Bell Laboratories technical memorandum.沃爾特在貝爾實驗室的技術備忘錄介紹了控制圖的概念。1928 Acceptance sampling methodology is developed and refined by H.F.Dodge and H.G.Roming at Bell Labs.H.F.道奇和H.G.漫游在貝爾實驗室開發和總結了驗收抽樣方法。1940 The U.S.War Department publishes a guide for using control charts to analyze process data.美國戰爭部出版了一份使用控制圖來分析處理數據指南。

1946 ASQC formed to promote use of quality improvement methods for products & service.建立美國質量控制協會以促進使用產品與服務質量改進方法。

1946–1949 Deming is invited to japan by the Economic and Scientific Services Section of the U.S.War Department to help occupation forces in rebuilding Japanese industry.He was invited to give statistical quality control seminars to Japanese industry.戴明被美國國防部的經濟和科學服務部邀請到日本幫助占領軍重建日本工業。他被邀請給日本工業的統計質量控制開研討會。

1951 Dr.A.V.Feigenbaum publishes the first edition of his book, Total Quality Control.G.E.P.Box & Wilson published work on designed experiments & process optimization methods.在1951年，費根鮑姆博士出版了他的第一本書---全面質量控制。威爾遜發明了工作流程優化設計和在線實驗的方法。

1960s Courses in statistical quality control become widespread in industrial engineering academic programs.Zero defects(ZD)programs are introduced in certain U.S.industries.在20世紀60年代的統計質量控制的廣泛的課程成為工業工程學術課程。零缺陷（ZD）計劃被美國工業產業引進。

1989 Motorola’s six-sigma initiative began.摩托羅拉開始倡議六西格瑪。

1990s ISO 9000 certification activities increase in U.S.industry;applicants for the Baldrige award grow steadily;many states sponsor quality awards based on the Baldrige criteria.上世紀90年代，在美國工業行業，ISO 9000認證活動增加；對波多里奇獎的申請穩步增長；許多國家贊助基于波多里奇標準的質量獎。

1995 Many undergraduate engineering programs require formal courses in statistical techniques, focusing on basic methods for process characterization and improvement.許多本科工程項目需要專注于過程特性和改進的基本方法 統計技術的正式課程。

1997 Motorola’s six-sigma approach spreads to other industries.1997年，摩托羅拉的六西格瑪方法擴展到其他行業。

1998 The American Societies for Quality Control becomes the

American Society for quality, attempting to indicate the broader aspects of the quality improvement field.1998年，美國質量控制協會成為美國質量學會，其試圖表明更廣泛的質量改善領域。

Statistical Methods統計方法 Statistical process control(SPC): use control charts to reduce variability & maintain measure of process quality within acceptable limits, namely, upper control limit(UCL)and lower control limit(LCL).統計過程控制（SPC）：使用控制圖來減少變化及維持質量測量在可接受的范圍內，即控制上限（UCL）和控制下限（LCL）。

Statistically designed experiment: used to discover key variables that influence quality characteristics of interest;systematically vary process controllable input factors to determine their effects on output product parameters.統計學設計的實驗：用于發現影響質量特性的關鍵變量，系統變化的過程可控的輸入因素，以確定其對輸出產品參數的影響。

Process modeling: captures the relationship between input and output variable of process;statistical such as regression or time-series analyses, also, neural network techniques, used to determine the nature &magnitude of adjustments required to bring process back into control.過程建模：捕捉過程中的輸入和輸出變量之間的關系；統計，如回歸或時間序列分析，神經網絡技術，用于確定控制過程中所需調整的性質和幅度。

Acceptance sampling: inspection & classification of sampled units, selected at random, from larger batch of product(lot)for the purpose of determining disposition of lot;decision may be to accept, reject, or rework lot;emphasizes conformance to requirements approach to quality control.驗收抽樣: 從大批產品(很多)檢查和分類抽樣單位,隨機選擇以確定處置方式, 決定可能是接受,拒絕,或返工;強調符合要求的質量控制方法。

Manufacturing Process Characteristics制造工藝特點

Random variations----caused by variability among operators, Raw materials, machine vibrations, and environmental changes;usually uncontrollable;regarded as process noise;no particular pattern or trend.隨機變化--由操作者，原材料，機器振動，和環境改變中的變化造成;通常無法控制的;被視為過程噪聲;沒有特定的模式或趨勢。

Assignable variations---exception from normal operating conditions, e.g, operator mistakes;defective raw materials;tool failures;machine malfunctions, can be traced to specific causes.可分配的變化---從正常工作條件下，例如，操作者錯誤的異常;有缺陷的原料;工具失效;機器故障，都可以追溯到具體原因。

Machining processes are capable of tolerances of +_0.002 in(+_0.05), e.g, sand castings generally have tolerances of 10 to 20 times those used for machined parts.加工過程能夠在（+_0.05）公差允許+-0.002，比如沙鑄件的公差通常是用于加工零件的公差的10至20倍。

Total Quality Management(TQM)全面質量管理

Total quality management(TQM)is a strategy for implementing and managing quality improvement activities on an organization wide basis.TQM began in the early 1980s, with the philosophies of Deming and Juran as the focal point.It evolved into a broader spectrum of concepts and ideas, involving participative organizations and work culture, customer focus, supplier quality improvement, integration of the quality system with business goals, and many other activities to focus all elements of the organization around the quality improvement goal.Typically, organizations that have implemented a TQM approach to quality improvement have quality councils or high-level teams that deal with strategic quality initiatives, workforce-level teams that focus on routine production or business activities, and cross-functional teams that address specific quality improvement issues.全面質量管理（TQM）在組織基礎中是一種實現和管理質量改進活動的戰略。全面質量管理始于上世紀80年代初，隨著戴明和朱蘭的理念為焦點。它演變成一個涉及參與組織和工作文化，關注客戶，供應商的質量改進，質量體系與業務目標的整合，以及許多其他的圍繞質量改進目標的組織的所有元素的活動的概念。通常情況下，已經實施了全面質量管理方法以提升質量的組織具有處理質量的戰略舉措的質量委員會或者高層團隊，聚焦日常生產、經營活動的勞動力水平的隊伍，解決具體的質量改進問題的跨 職能團隊。

機械專業詞匯

Manufacturing process 制造工藝 Serviceability 維護性

Conformance to standards 標準一致 Quality engineering 質量工程 Measured value 測量值 Nominal value 真值 Multi-disciplinary 多學科的 Concurrent engineering 并行工程 Standardized parts 標準件 Six-sigma 六西格瑪 LSL 下限 USL 上限

ISO9000 質量保證體系9000 Process modeling 過程建模 Process control 過程控制 TQM全面質量管理 Sand casting 沙鑄件

Acceptance sampling 進料抽樣實驗 Assignable variation 系統變差 Critical dimension 臨界大小 科技特殊句式 1.動名詞做主語

Understanding and improving quality are key factors leading to business success, growth, and enhanced competitiveness.2.非謂語動詞做定語

Quality----characteristic or property consisting of several well-defined technical and aesthetic, hence subjective, considerations;conformance to design(customer)requirement.3.復雜長句

This also leads to much less focus on the customer and more of a ―conformance-to-specifications‖ approach to quality, regardless of whether the product, even when produced to standards, was actually ―fit-for use‖ by the customer.4.名詞短語

There are two general aspects of fitness for use: quality of design and quality of conformance.5.復雜長句 Organizations that have implemented a TQM approach to quality improvement have quality councils or high-level teams that deal with strategic quality initiatives, workforce-level teams that focus on routine production or business activities, and cross-functional teams that address specific quality improvement issues.典型句式

1.定義句式

Quality by design intent refers to the various grades or levels of quality that are intentionally determined by design.Paradigm refers to models of inquiry that guides scientific work

2.滿足標準

The traditional definition of quality is based on the viewpoint that products and services must meet the requirement of those who use them.All structural steel, plate and sheet meet the requirements of certain specifications.3.比例關系

Quality is inversely proportional to variability.Al Most objects are big in proportion to the size of an atom but small in proportion to the size of the sun.4.圖表所占比例

The Japanese plant produced transmissions for which the same critical characteristics take up only about 25% of the specification band.Girl students accounted for 47.3 percent of total primary school enrollment.Figure 4.2 gives the results of the experiment.5.研究表明

An analysis of warranty claims and repair costs indicated that there was a striking difference between the two sources of production.A study indicated that the successful language learners are same at many aspects.6.結論

Therefore, an alternate and frequently very useful definition is that quality improvement is the reduction of waste.It can be concluded that baud rate is very important to the telephone engineer.7.舉例

For example, consider the wasted money, time, and effort that is associated with the repairs represented in Figure 5.1.For example, consultants and freelancers interviewed for this article set targets from$ 50 to$ 300 per hour.8.相關性

This definition has become associated more with the conformance aspect of quality than with design.The density of a soil is directly associated to its bearing capability.9.圖表引用

Figure 5.2 is generally representative of the results of this study.Figure 4.2 gives the results of the experiment.10.It---that語句

It is often very important to differentiate these different dimensions of quality.It is evident that a well lubricated bearing turns more easily than a dry one.

第四篇：機械英語翻譯

機械英語翻譯.txt你無法改變別人，但你可以改變自己；你無法改變天氣，但你可以改變心情；你無法改變生命長度，但你可以拓展它的寬度。第一單元 ? Types of Materials 材料的類型

Materials may be grouped in several ways.Scientists often classify materials by their state: solid, liquid, or gas.They also separate them into organic(once living)and inorganic(never living)materials.材料可以按多種方法分類?？茖W家常根據狀態將材料分為：固體、液體或氣體。他們也把材料分為有機材料(曾經有生命的)和無機材料(從未有生命的)。

For industrial purposes, materials are divided into engineering materials or nonengineering materials.Engineering materials are those used in manufacture and become parts of products.就工業效用而言，材料被分為工程材料和非工程材料。那些用于加工制造并成為產品組成部分的就是工程材料。

Nonengineering materials are the chemicals, fuels, lubricants, and other materials used in the manufacturing process, which do not become part of the product.非工程材料則是化學品、燃料、潤滑劑以及其它用于加工制造過程但不成為產品組成部分的材料。

Engineering materials may be further subdivided into: ①Metal ②Ceramics ③Composite ④Polymers, etc.工程材料還能進一步細分為：①金屬材料②陶瓷材料③復合材料 ④聚合材料，等等。? Metals and Metal Alloys 金屬和金屬合金

Metals are elements that generally have good electrical and thermal conductivity.Many metals have high strength, high stiffness, and have good ductility.金屬就是通常具有良好導電性和導熱性的元素。許多金屬具有高強度、高硬度以及良好的延展性。

Some metals, such as iron, cobalt and nickel, are magnetic.At low temperatures, some metals and intermetallic compounds become superconductors.某些金屬能被磁化，例如鐵、鈷和鎳。在極低的溫度下，某些金屬和金屬化合物能轉變成超導體。

What is the difference between an alloy and a pure metal? Pure metals are elements which come from a particular area of the periodic table.Examples of pure metals include copper in electrical wires and aluminum in cooking foil and beverage cans.合金與純金屬的區別是什么？純金屬是在元素周期表中占據特定位置的元素。例如電線中的銅和制造烹飪箔及飲料罐的鋁。

Alloys contain more than one metallic element.Their properties can be changed by changing the elements present in the alloy.Examples of metal alloys include stainless steel which is an alloy of iron, nickel, and chromium;and gold jewelry which usually contains an alloy of gold and nickel.合金包含不止一種金屬元素。合金的性質能通過改變其中存在的元素而改變。金屬合金的例子有：不銹鋼是一種鐵、鎳、鉻的合金，以及金飾品通常含有金鎳合金。Why are metals and alloys used? Many metals and alloys have high densities and are used in applications which require a high mass-to-volume ratio.為什么要使用金屬和合金？許多金屬和合金具有高密度，因此被用在需要較高質量體積比的場合。

Some metal alloys, such as those based on aluminum, have low densities and are used in aerospace applications for fuel economy.Many alloys also have high fracture toughness, which means they can withstand impact and are durable.某些金屬合金，例如鋁基合金，其密度低，可用于航空航天以節約燃料。許多合金還具有高斷裂韌性，這意味著它們能經得起沖擊并且是耐用的。

What are some important properties of metals? Density is defined as a material’s mass divided by its volume.Most metals have relatively high densities, especially compared to polymers.金屬有哪些重要特性？

密度定義為材料的質量與其體積之比。大多數金屬密度相對較高，尤其是和聚合物相比較而言。

Materials with high densities often contain atoms with high atomic numbers, such as gold or lead.However, some metals such as aluminum or magnesium have low densities, and are used in applications that require other metallic properties but also require low weight.高密度材料通常由較大原子序數原子構成，例如金和鉛。然而，諸如鋁和鎂之類的一些金屬則具有低密度，并被用于既需要金屬特性又要求重量輕的場合。Fracture toughness can be described as a material’s ability to avoid fracture, especially when a flaw is introduced.Metals can generally contain nicks and dents without weakening very much, and are impact resistant.A football player counts on this when he trusts that his facemask won’t shatter.斷裂韌性可以描述為材料防止斷裂特別是出現缺陷時不斷裂的能力。金屬一般能在有缺口和凹痕的情況下不顯著削弱，并且能抵抗沖擊。橄欖球運動員據此相信他的面罩不會裂成碎片。

Plastic deformation is the ability of bend or deform before breaking.As engineers, we usually design materials so that they don’t deform under normal conditions.You don’t want your car to lean to the east after a strong west wind.塑性變形就是在斷裂前彎曲或變形的能力。作為工程師，設計時通常要使材料在正常條件下不變形。沒有人愿意一陣強烈的西風過后自己的汽車向東傾斜。

However, sometimes we can take advantage of plastic deformation.The crumple zones in a car absorb energy by undergoing plastic deformation before they break.然而，有時我們也能利用塑性變形。汽車上壓皺的區域在它們斷裂前通過經歷塑性變形來吸收能量。

The atomic bonding of metals also affects their properties.In metals, the outer valence electrons are shared among all atoms, and are free to travel everywhere.Since electrons conduct heat and electricity, metals make good cooking pans and electrical wires.金屬的原子連結對它們的特性也有影響。在金屬內部，原子的外層階電子由所有原子共享并能到處自由移動。由于電子能導熱和導電，所以用金屬可以制造好的烹飪鍋和電線。It is impossible to see through metals, since these valence electrons absorb any photons of light which reach the metal.No photons pass through.因為這些階電子吸收到達金屬的光子，所以透過金屬不可能看得見。沒有光子能通過金屬。Alloys are compounds consisting of more than one metal.Adding other metals can affect the density, strength, fracture toughness, plastic deformation, electrical conductivity and environmental degradation.合金是由一種以上金屬組成的混合物。加一些其它金屬能影響密度、強度、斷裂韌性、塑性變形、導電性以及環境侵蝕。

For example, adding a small amount of iron to aluminum will make it stronger.Also, adding some chromium to steel will slow the rusting process, but will make it more brittle.例如，往鋁里加少量鐵可使其更強。同樣，在鋼里加一些鉻能減緩它的生銹過程，但也將使它更脆。

? Ceramics and Glasses 陶瓷和玻璃 A ceramic is often broadly defined as any inorganic nonmetallic material． By this definition, ceramic materials would also include glasses;however, many materials scientists add the stipulation that “ceramic” must also be crystalline.陶瓷通常被概括地定義為無機的非金屬材料。照此定義，陶瓷材料也應包括玻璃；然而許多材料科學家添加了“陶瓷”必須同時是晶體物組成的約定。

A glass is an inorganic nonmetallic material that does not have a crystalline structure.Such materials are said to be amorphous.玻璃是沒有晶體狀結構的無機非金屬材料。這種材料被稱為非結晶質材料。Properties of Ceramics and Glasses Some of the useful properties of ceramics and glasses include high melting temperature, low density, high strength, stiffness, hardness, wear resistance, and corrosion resistance.陶瓷和玻璃的特性

高熔點、低密度、高強度、高剛度、高硬度、高耐磨性和抗腐蝕性是陶瓷和玻璃的一些有用特性。

Many ceramics are good electrical and thermal insulators.Some ceramics have special properties: some ceramics are magnetic materials;some are piezoelectric materials;and a few special ceramics are superconductors at very low temperatures.Ceramics and glasses have one major drawback: they are brittle.許多陶瓷都是電和熱的良絕緣體。某些陶瓷還具有一些特殊性能：有些是磁性材料，有些是壓電材料，還有些特殊陶瓷在極低溫度下是超導體。陶瓷和玻璃都有一個主要的缺點：它們容易破碎。

Ceramics are not typically formed from the melt.This is because most ceramics will crack extensively(i.e.form a powder)upon cooling from the liquid state.陶瓷一般不是由熔化形成的。因為大多數陶瓷在從液態冷卻時將會完全破碎(即形成粉末)。

Hence, all the simple and efficient manufacturing techniques used for glass production such as casting and blowing, which involve the molten state, cannot be used for the production of crystalline ceramics.Instead, “sintering” or “firing” is the process typically used.因此，所有用于玻璃生產的簡單有效的—諸如澆鑄和吹制這些涉及熔化的技術都不能用于由晶體物組成的陶瓷的生產。作為替代，一般采用“燒結”或“焙燒”工藝。

In sintering, ceramic powders are processed into compacted shapes and then heated to temperatures just below the melting point.At such temperatures, the powders react internally to remove porosity and fully dense articles can be obtained.在燒結過程中，陶瓷粉末先擠壓成型然后加熱到略低于熔點溫度。在這樣的溫度下，粉末內部起反應去除孔隙并得到十分致密的物品。

An optical fiber contains three layers: a core made of highly pure glass with a high refractive index for the light to travel, a middle layer of glass with a lower refractive index known as the cladding which protects the core glass from scratches and other surface imperfections, and an out polymer jacket to protect the fiber from damage.光導纖維有三層：核心由高折射指數高純光傳輸玻璃制成，中間層為低折射指數玻璃，是保護核心玻璃表面不被擦傷和完整性不被破壞的所謂覆層，外層是聚合物護套，用于保護光導纖維不受損。

In order for the core glass to have a higher refractive index than the cladding, the core glass is doped with a small, controlled amount of an impurity, or dopant, which causes light to travel slower, but does not absorb the light.為了使核心玻璃有比覆層大的折射指數，在其中摻入微小的、可控數量的能減緩光速而不會吸收光線的雜質或攙雜劑。

Because the refractive index of the core glass is greater than that of the cladding, light traveling in the core glass will remain in the core glass due to total internal reflection as long as the light strikes the core/cladding interface at an angle greater than the critical angle.由于核心玻璃的折射指數比覆層大，只要在全內反射過程中光線照射核心/覆層分界面的角度比臨界角大，在核心玻璃中傳送的光線將仍保留在核心玻璃中。

The total internal reflection phenomenon, as well as the high purity of the core glass, enables light to travel long distances with little loss of intensity.全內反射現象與核心玻璃的高純度一樣，使光線幾乎無強度損耗傳遞長距離成為可能。? Composites 復合材料

Composites are formed from two or more types of materials.Examples include polymer/ceramic and metal/ceramic composites.Composites are used because overall properties of the composites are superior to those of the individual components.復合材料由兩種或更多材料構成。例子有聚合物/陶瓷和金屬/陶瓷復合材料。之所以使用復合材料是因為其全面性能優于組成部分單獨的性能。

For example: polymer/ceramic composites have a greater modulus than the polymer component, but aren’t as brittle as ceramics.Two types of composites are: fiber-reinforced composites and particle-reinforced composites.例如：聚合物/陶瓷復合材料具有比聚合物成分更大的模量，但又不像陶瓷那樣易碎。

復合材料有兩種：纖維加強型復合材料和微粒加強型復合材料。Fiber-reinforced Composites Reinforcing fibers can be made of metals, ceramics, glasses, or polymers that have been turned into graphite and known as carbon fibers.Fibers increase the modulus of the matrix material.纖維加強型復合材料

加強纖維可以是金屬、陶瓷、玻璃或是已變成石墨的被稱為碳纖維的聚合物。纖維能加強基材的模量。

The strong covalent bonds along the fiber’s length give them a very high modulus in this direction because to break or extend the fiber the bonds must also be broken or moved.沿著纖維長度有很強結合力的共價結合在這個方向上給予復合材料很高的模量，因為要損壞或拉伸纖維就必須破壞或移除這種結合。

Fibers are difficult to process into composites, making fiber-reinforced composites relatively expensive.把纖維放入復合材料較困難，這使得制造纖維加強型復合材料相對昂貴。Fiber-reinforced composites are used in some of the most advanced, and therefore most expensive sports equipment, such as a time-trial racing bicycle frame which consists of carbon fibers in a thermoset polymer matrix.纖維加強型復合材料用于某些最先進也是最昂貴的運動設備，例如計時賽競賽用自行車骨架就是用含碳纖維的熱固塑料基材制成的。

Body parts of race cars and some automobiles are composites made of glass fibers(or fiberglass)in a thermoset matrix.競賽用汽車和某些機動車的車體部件是由含玻璃纖維(或玻璃絲)的熱固塑料基材制成的。Fibers have a very high modulus along their axis, but have a low modulus perpendicular to their axis.Fiber composite manufacturers often rotate layers of fibers to avoid directional variations in the modulus.纖維在沿著其軸向有很高的模量，但垂直于其軸向的模量卻較低。纖維復合材料的制造者往往旋轉纖維層以防模量產生方向變化。Particle-reinforced composites Particles used for reinforcing include ceramics and glasses such as small mineral particles, metal particles such as aluminum, and amorphous materials, including polymers and carbon black.微粒加強型復合材料

用于加強的微粒包含了陶瓷和玻璃之類的礦物微粒，鋁之類的金屬微粒以及包括聚合物和碳黑的非結晶質微粒。

Particles are used to increase the modulus of the matrix, to decrease the permeability of the matrix, to decrease the ductility of the matrix.An example of particle-reinforced composites is an automobile tire which has carbon black particles in a matrix of polyisobutylene elastomeric polymer.微粒用于增加基材的模量、減少基材的滲透性和延展性。微粒加強型復合材料的一個例子是機動車胎，它就是在聚異丁烯人造橡膠聚合物基材中加入了碳黑微粒。? Polymers 聚合材料

A polymer has a repeating structure, usually based on a carbon backbone.The repeating structure results in large chainlike molecules.Polymers are useful because they are lightweight, corrosion resistant, easy to process at low temperatures and generally inexpensive.聚合物具有一般是基于碳鏈的重復結構。這種重復結構產生鏈狀大分子。由于重量輕、耐腐蝕、容易在較低溫度下加工并且通常較便宜，聚合物是很有用的。

Some important characteristics of polymers include their size(or molecular weight), softening and melting points, crystallinity, and structure.The mechanical properties of polymers generally include low strength and high toughness.Their strength is often improved using reinforced composite structures.聚合材料具有一些重要特性，包括尺寸(或分子量)、軟化及熔化點、結晶度和結構。聚合材料的機械性能一般表現為低強度和高韌性。它們的強度通常可采用加強復合結構來改善。

Important Characteristics of Polymers Size.Single polymer molecules typically have molecular weights between 10,000 and 1,000,000g/mol—that can be more than 2,000 repeating units depending on the polymer structure!聚合材料的重要特性

尺寸：單個聚合物分子一般分子量為10,000到1,000,000g/mol之間，具體取決于聚合物的結構—這可以比2,000個重復單元還多。The mechanical properties of a polymer are significantly affected by the molecular weight, with better engineering properties at higher molecular weights.聚合物的分子量極大地影響其機械性能，分子量越大，工程性能也越好。Thermal transitions.The softening point(glass transition temperature)and the melting point of a polymer will determine which it will be suitable for applications.These temperatures usually determine the upper limit for which a polymer can be used.熱轉換性：聚合物的軟化點(玻璃狀轉化溫度)和熔化點決定了它是否適合應用。這些溫度通常決定聚合物能否使用的上限。For example, many industrially important polymers have glass transition temperatures near the boiling point of water(100℃, 212℉), and they are most useful for room temperature applications.Some specially engineered polymers can withstand temperatures as high as 300℃(572℉).例如，許多工業上的重要聚合物其玻璃狀轉化溫度接近水的沸點(100℃, 212℉)，它們被廣泛用于室溫下。而某些特別制造的聚合物能經受住高達300℃(572℉)的溫度。

Crystallinity.Polymers can be crystalline or amorphous, but they usually have a combination of crystalline and amorphous structures(semi-crystalline).結晶度：聚合物可以是晶體狀的或非結晶質的，但它們通常是晶體狀和非結晶質結構的結合物(半晶體)。

Interchain interactions.The polymer chains can be free to slide past one another(thermo-plastic)or they can be connected to each other with crosslinks(thermoset or elastomer).Thermo-plastics can be reformed and recycled, while thermosets and elastomers are not reworkable.原子鏈間的相互作用：聚合物的原子鏈可以自由地彼此滑動(熱可塑性)或通過交鍵互相連接(熱固性或彈性)。熱可塑性材料可以重新形成和循環使用，而熱固性與彈性材料則是不能再使用的。

Intrachain structure.The chemical structure of the chains also has a tremendous effect on the properties.Depending on the structure the polymer may be hydrophilic or hydrophobic(likes or hates water), stiff or flexible, crystalline or amorphous, reactive or unreactive.鏈內結構：原子鏈的化學結構對性能也有很大影響。根據各自的結構不同，聚合物可以是親水的或憎水的(喜歡或討厭水)、硬的或軟的、晶體狀的或非結晶質的、易起反應的或不易起反應的。

第二單元

The understanding of heat treatment is embraced by the broader study of metallurgy.Metallurgy is the physics, chemistry, and engineering related to metals from ore extraction to the final product.對熱處理的理解包含于對冶金學較廣泛的研究。冶金學是物理學、化學和涉及金屬從礦石提煉到最后產物的工程學。

Heat treatment is the operation of heating and cooling a metal in its solid state to change its physical properties.According to the procedure used, steel can be hardened to resist cutting action and abrasion, or it can be softened to permit machining.熱處理是將金屬在固態加熱和冷卻以改變其物理性能的操作。按所采用的步驟，鋼可以通過硬化來抵抗切削和磨損，也可以通過軟化來允許機加工。

With the proper heat treatment internal stresses may be removed, grain size reduced, toughness increased, or a hard surface produced on a ductile interior.The analysis of the steel must be known because small percentages of certain elements, notably carbon, greatly affect the physical properties.使用合適的熱處理可以去除內應力、細化晶粒、增加韌性或在柔軟材料上覆蓋堅硬的表面。因為某些元素(尤其是碳)的微小百分比極大地影響物理性能，所以必須知道對鋼的分析。Alloy steel owe their properties to the presence of one or more elements other than carbon, namely nickel, chromium, manganese, molybdenum, tungsten, silicon, vanadium, and copper.Because of their improved physical properties they are used commercially in many ways not possible with carbon steels.合金鋼的性質取決于其所含有的除碳以外的一種或多種元素，如鎳、鉻、錳、鉬、鎢、硅、釩和銅。由于合金鋼改善的物理性能，它們被大量使用在許多碳鋼不適用的地方。The following discussion applies principally to the heat treatment of ordinary commercial steels known as plain carbon steels.With this process the rate of cooling is the controlling factor, rapid cooling from above the critical range results in hard structure, whereas very slow cooling produces the opposite effect.下列討論主要針對被稱為普通碳鋼的工業用鋼而言。熱處理時冷卻速率是控制要素，從高于臨界溫度快速冷卻導致堅硬的組織結構，而緩慢冷卻則產生相反效果。? A Simplified Iron-carbon Diagram 簡化鐵碳狀態圖

If we focus only on the materials normally known as steels, a simplified diagram is often used.如果只把注意力集中于一般所說的鋼上，經常要用到簡化鐵碳狀態圖。

Those portions of the iron-carbon diagram near the delta region and those above 2% carbon content are of little importance to the engineer and are deleted.A simplified diagram, such as the one in Fig.2.1, focuses on the eutectoid region and is quite useful in understanding the properties and processing of steel.鐵碳狀態圖中靠近三角區和含碳量高于2%的那些部分對工程師而言不重要，因此將它們刪除。如圖2.1所示的簡化鐵碳狀態圖將焦點集中在共析區，這對理解鋼的性能和處理是十分有用的。

The key transition described in this diagram is the decomposition of single-phase austenite(γ)to the two-phase ferrite plus carbide structure as temperature drops.在此圖中描述的關鍵轉變是單相奧氏體(γ)隨著溫度下降分解成兩相鐵素體加滲碳體組織結構。

Control of this reaction, which arises due to the drastically different carbon solubility of austenite and ferrite, enables a wide range of properties to be achieved through heat treatment.控制這一由于奧氏體和鐵素體的碳溶解性完全不同而產生的反應，使得通過熱處理能獲得很大范圍的特性。To begin to understand these processes, consider a steel of the eutectoid composition, 0.77% carbon, being slow cooled along line x-x’ in Fig.2.1.At the upper temperatures, only austenite is present, the 0.77% carbon being dissolved in solid solution with the iron.When the steel cools to 727℃(1341℉), several changes occur simultaneously.為了理解這些過程，考慮含碳量為0.77%的共析鋼，沿著圖2.1的x-x’線慢慢冷卻。在較高溫度時，只存在奧氏體，0.77%的碳溶解在鐵里形成固溶體。當鋼冷卻到727℃(1341℉)時，將同時發生若干變化。

The iron wants to change from the FCC austenite structure to the BCC ferrite structure, but the ferrite can only contain 0.02% carbon in solid solution.鐵需要從面心立方體奧氏體結構轉變為體心立方體鐵素體結構，但是鐵素體只能容納固溶體狀態的0.02%的碳。

The rejected carbon forms the carbon-rich cementite intermetallic with composition Fe3C.In essence, the net reaction at the eutectoid is austenite 0.77%C→ferrite 0.02%C+cementite 6.67%C.被析出的碳與金屬化合物Fe3C形成富碳的滲碳體。本質上，共析體的基本反應是奧氏體0.77%的碳→鐵素體0.02%的碳+滲碳體6.67%的碳。

Since this chemical separation of the carbon component occurs entirely in the solid state, the resulting structure is a fine mechanical mixture of ferrite and cementite.Specimens prepared by polishing and etching in a weak solution of nitric acid and alcohol reveal the lamellar structure of alternating plates that forms on slow cooling.由于這種碳成分的化學分離完全發生在固態中，產生的組織結構是一種細致的鐵素體與滲碳體的機械混合物。通過打磨并在弱硝酸酒精溶液中蝕刻制備的樣本顯示出由緩慢冷卻形成的交互層狀的薄片結構。

This structure is composed of two distinct phases, but has its own set of characteristic properties and goes by the name pearlite, because of its resemblance to mother-of-pearl at low magnification.這種結構由兩種截然不同的狀態組成，但它本身具有一系列特性，且因與低倍數放大時的珠母層有類同之處而被稱為珠光體。Steels having less than the eutectoid amount of carbon(less than 0.77%)are known as hypo-eutectoid steels.Consider now the transformation of such a material represented by cooling along line y-y’ in Fig.2.1.含碳量少于共析體(低于0.77%)的鋼稱為亞共析鋼。現在來看這種材料沿著圖2.1中y-y’ 線冷卻的轉變情況。

At high temperatures, the material is entirely austenite, but upon cooling enters a region where the stable phases are ferrite and austenite.Tie-line and level-law calculations show that low-carbon ferrite nucleates and grows, leaving the remaining austenite richer in carbon.在較高溫度時，這種材料全部是奧氏體，但隨著冷卻就進入到鐵素體和奧氏體穩定狀態的區域。由截線及杠桿定律分析可知，低碳鐵素體成核并長大，剩下含碳量高的奧氏體。

At 727℃(1341℉), the austenite is of eutectoid composition(0.77% carbon)and further cooling transforms the remaining austenite to pearlite.The resulting structure is a mixture of primary or pro-eutectoid ferrite(ferrite that formed above the eutectoid reaction)and regions of pearlite.在727℃(1341℉)時，奧氏體為共析組成(含碳量0.77%)，再冷卻剩余的奧氏體就轉化為珠光體。作為結果的組織結構是初步的共析鐵素體(在共析反應前的鐵素體)和部分珠光體的混合物。

Hypereutectoid steels are steels that contain greater than the eutectoid amount of carbon.When such steel cools, as shown in z-z’ of Fig.2.1 the process is similar to the hypo-eutectoid case, except that the primary or pro-eutectoid phase is now cementite instead of ferrite.過共析鋼是含碳量大于共析量的鋼。當這種鋼冷卻時，就像圖2.1的z-z’線所示，除了初步的共析狀態用滲碳體取代鐵素體外，其余類似亞共析鋼的情況。

As the carbon-rich phase forms, the remaining austenite decreases in carbon content, reaching the eutectoid composition at 727℃(1341℉).As before, any remaining austenite transforms to pearlite upon slow cooling through this temperature.隨著富碳部分的形成，剩余奧氏體含碳量減少，在727℃(1341℉)時達到共析組織。就像以前說的一樣，當緩慢冷卻到這溫度時所有剩余奧氏體轉化為珠光體。

It should be remembered that the transitions that have been described by the phase diagrams are for equilibrium conditions, which can be approximated by slow cooling.With slow heating, these transitions occur in the reverse manner.應該記住由狀態圖描述的這種轉化只適合于通過緩慢冷卻的近似平衡條件。如果緩慢加熱，則以相反的方式發生這種轉化。However, when alloys are cooled rapidly, entirely different results may be obtained, because sufficient time is not provided for the normal phase reactions to occur, in such cases, the phase diagram is no longer a useful tool for engineering analysis.然而，當快速冷卻合金時，可能得到完全不同的結果。因為沒有足夠的時間讓正常的狀態反應發生，在這種情況下對工程分析而言狀態圖不再是有用的工具。? Hardening 淬火

Hardening is the process of heating a piece of steel to a temperature within or above its critical range and then cooling it rapidly.淬火就是把鋼件加熱到或超過它的臨界溫度范圍，然后使其快速冷卻的過程。If the carbon content of the steel is known, the proper temperature to which the steel should be heated may be obtained by reference to the iron-iron carbide phase diagram.However, if the composition of the steel is unknown, a little preliminary experimentation may be necessary to determine the range.如果鋼的含碳量已知，鋼件合適的加熱溫度可參考鐵碳合金狀態圖得到。然而當鋼的成分不知道時，則需做一些預備試驗來確定其溫度范圍。

A good procedure to follow is to heat-quench a number of small specimens of the steel at various temperatures and observe the result, either by hardness testing or by microscopic examination.When the correct temperature is obtained, there will be a marked change in hardness and other properties.要遵循的合適步驟是將這種鋼的一些小試件加熱到不同的溫度后淬火，再通過硬度試驗或顯微鏡檢查觀測結果。一旦獲得正確的溫度，硬度和其它性能都將有明顯的變化。

In any heat-treating operation the rate of heating is important.Heat flows from the exterior to the interior of steel at a definite rate.If the steel is heated too fast, the outside becomes hotter than the interior and uniform structure cannot be obtained.在任何熱處理作業中，加熱的速率都是重要的。熱量以一定的速率從鋼的外部傳導到內部。如果鋼被加熱得太快，其外部比內部熱就不能得到均勻的組織結構。

If a piece is irregular in shape, a slow rate is all the more essential to eliminate warping and cracking.The heavier the section, the longer must be the heating time to achieve uniform results.如果工件形狀不規則，為了消除翹曲和開裂最根本的是加熱速率要緩慢。截面越厚，加熱的時間就要越長才能達到均勻的結果。

Even after the correct temperature has been reached, the piece should be held at that temperature for a sufficient period of time to permit its thickest section to attain a uniform temperature.即使加熱到正確的溫度后，工件也應在此溫度下保持足夠時間以讓其最厚截面達到相同溫度。The hardness obtained from a given treatment depends on the quenching rate, the carbon content, and the work size.In alloy steels the kind and amount of alloying element influences only the hardenability(the ability of the workpiece to be hardened to depths)of the steel and does not affect the hardness except in unhardened or partially hardened steels.通過給定的熱處理所得到的硬度取決于淬火速率、含碳量和工件尺寸。除了非淬硬鋼或部分淬硬鋼外，合金鋼中合金元素的種類及含量僅影響鋼的淬透性(工件被硬化到深層的能力)而不影響硬度。

Steel with low carbon content will not respond appreciably to hardening treatment.As the carbon content in steel increases up to around 0.60%, the possible hardness obtainable also increases.含碳量低的鋼對淬火處理沒有明顯的反應。隨著鋼的含碳量增加到大約0.60%，可能得到的硬度也增加。

Above this point the hardness can be increased only slightly, because steels above the eutectoid point are made up entirely of pearlite and cementite in the annealed state.Pearlite responds best to heat-treating operations;and steel composed mostly of pearlite can be transformed into a hard steel.高于此點，由于超過共析點鋼完全由珠光體和退火狀態的滲碳體組成，硬度增加并不多。珠光體對熱處理作業響應最好；基本由珠光體組成的鋼能轉化成硬質鋼。As the size of parts to be hardened increases, the surface hardness decreases somewhat even though all other conditions have remained the same.There is a limit to the rate of heat flow through steel.即使所有其它條件保持不變，隨著要淬火的零件尺寸的增加其表面硬度也會有所下降。熱量在鋼中的傳導速率是有限的。No matter how cool the quenching medium may be, if the heat inside a large piece cannot escape faster than a certain critical rate, there is a definite limit to the inside hardness.However, brine or water quenching is capable of rapidly bringing the surface of the quenched part to its own temperature and maintaining it at or close to this temperature.無論淬火介質怎么冷，如果在大工件中的熱量不能比特定的臨界速率更快散發，那它內部硬度就會受到明確限制。然而鹽水或水淬火能夠將被淬零件的表面迅速冷卻至本身溫度并將其保持或接近此溫度。Under these circumstances there would always be some finite depth of surface hardening regardless of size.This is not true in oil quenching, when the surface temperature may be high during the critical stages of quenching.在這種情況下不管零件尺寸如何，其表面總歸有一定深度被硬化。但油淬情況就不是如此，因為油淬時在淬火臨界階段零件表面的溫度可能仍然很高。? Tempering 回火

Steel that has been hardened by rapid quenching is brittle and not suitable for most uses.By tempering or drawing, the hardness and brittleness may be reduced to the desired point for service conditions．

快速淬火硬化的鋼是硬而易碎的，不適合大多數場合使用。通過回火，硬度和脆性可以降低到使用條件所需要的程度。

As these properties are reduced there is also a decrease in tensile strength and an increase in the ductility and toughness of the steel.The operation consists of reheating quench-hardened steel to some temperature below the critical range followed by any rate of cooling.隨著這些性能的降低，拉伸強度也降低而鋼的延展性和韌性則會提高。回火作業包括將淬硬鋼重新加熱到低于臨界范圍的某一溫度然后以任意速率冷卻。

Although this process softens steel, it differs considerably from annealing in that the process lends itself to close control of the physical properties and in most cases does not soften the steel to the extent that annealing would.The final structure obtained from tempering a fully hardened steel is called tempered martensite.雖然這過程使鋼軟化，但它與退火是大不相同的，因為回火適合于嚴格控制物理性能并在大多數情況下不會把鋼軟化到退火那種程度。回火完全淬硬鋼得到的最終組織結構被稱為回火馬氏體。

Tempering is possible because of the instability of the martensite, the principal constituent of hardened steel.Low-temperature draws, from 300℉ to 400℉(150℃~205℃), do not cause much decrease in hardness and are used principally to relieve internal strains.由于馬氏體這一淬硬鋼主要成分的不穩定性，使得回火成為可能。低溫回火，300℉到400℉(150℃~205℃)，不會引起硬度下降很多，主要用于減少內部應變。As the tempering temperatures are increased, the breakdown of the martensite takes place at a faster rate, and at about 600℉(315℃)the change to a structure called tempered martensite is very rapid.The tempering operation may be described as one of precipitation and agglomeration or coalescence of cementite.隨著回火溫度的提高，馬氏體以較快的速率分解，并在大約600℉(315℃)迅速轉變為被稱為回火馬氏體的結構。回火作業可以描述為滲碳體析出和凝聚或聚結的過程。

A substantial precipitation of cementite begins at 600℉(315℃), which produces a decrease in hardness.Increasing the temperature causes coalescence of the carbides with continued decrease in hardness.滲碳體的大量析出開始于600℉(315℃)，這使硬度下降。溫度的上升會使碳化物聚結而硬度繼續降低。

In the process of tempering, some consideration should be given to time as well as to temperature.Although most of the softening action occurs in the first few minutes after the temperature is reached, there is some additional reduction in hardness if the temperature is maintained for a prolonged time.在回火過程中，不但要考慮溫度而且要考慮時間。雖然大多數軟化作用發生在達到所需溫度后的最初幾分鐘，但如果此溫度維持一段延長時間，仍會有些額外的硬度下降。Usual practice is to heat the steel to the desired temperature and hold it there only long enough to have it uniformly heated.通常的做法是將鋼加熱到所需溫度并且僅保溫到正好使其均勻受熱。

Two special processes using interrupted quenching are a form of tempering.In both, the hardened steel is quenched in a salt bath held at a selected lower temperature before being allowed to cool.These processes, known as austempering and martempering, result in products having certain desirable physical properties.兩種采用中斷淬火的特殊工藝也是回火的形式。這兩種工藝中，淬硬鋼在其被允許冷卻前先在一選定的較低溫度鹽浴淬火。這兩種分別被稱為奧氏體回火和馬氏體回火的工藝，能使產品具有特定所需的物理性能。? Annealing 退火

The primary purpose of annealing is to soften hard steel so that it may be machined or cold worked.退火的主要目的是使堅硬的鋼軟化以便機加工或冷作。

This is usually accomplished by heating the steel too slightly above the critical temperature, holding it there until the temperature of the piece is uniform throughout, and then cooling at a slowly controlled rate so that the temperature of the surface and that of the center of the piece are approximately the same.通常是非常緩慢地將鋼加熱到臨界溫度以上，并將其在此溫度下保持到工件全部均勻受熱，然后以受控的速率慢慢地冷卻，這樣使得工件表面和內部的溫度近似相同。

This process is known as full annealing because it wipes out all trace of previous structure, refines the crystalline structure, and softens the metal.Annealing also relieves internal stresses previously set up in the metal.這過程被稱為完全退火，因為它去除了以前組織結構的所有痕跡、細化晶粒并軟化金屬。退火也釋放了先前在金屬中的內應力。

The temperature to which a given steel should be heated in annealing depends on its composition;for carbon steels it can be obtained readily from the partial iron-iron carbide equilibrium diagram.When the annealing temperature has been reached, the steel should be held there until it is uniform throughout.給定的鋼其退火溫度取決于它的成分；對碳鋼而言可容易地從局部的鐵碳合金平衡圖得到。達到退火溫度后，鋼應當保持在此溫度等到全部均勻受熱。This usually takes about 45min for each inch(25mm)of thickness of the largest section.For maximum softness and ductility the cooling rate should be very slow, such as allowing the parts to cool down with the furnace.The higher the carbon content, the slower this rate must be.加熱時間一般以工件的最大截面厚度計每英寸(25mm)大約需45min。為了得到最大柔軟性和延展性冷卻速率應該很慢，比如讓零件與爐子一起冷下來。含碳量越高，冷卻的速率必須越慢。

The heating rate should be consistent with the size and uniformity of sections, so that the entire part is brought up to temperature as uniformly as possible.加熱的速率也應與截面的尺寸及均勻程度相協調，這樣才能使整個零件盡可能均勻地加熱。? Normalizing and Spheroidizing 正火和球化

The process of normalizing consists of heating the steel about 50℉ to 100℉(10℃~40℃)above the upper critical range and cooling in still air to room temperature.正火處理包括先將鋼加熱到高于上臨界區50℉到100℉(10℃~40℃)然后在靜止的空氣中冷卻到室溫。

This process is principally used with low-and medium-carbon steels as well as alloy steels to make the grain structure more uniform, to relieve internal stresses, or to achieve desired results in physical properties.Most commercial steels are normalized after being rolled or cast.退火主要用于低碳鋼、中碳鋼及合金鋼，使晶粒結構更均勻、釋放內應力或獲得所需的物理特性。大多數商業鋼材在軋制或鑄造后都要退火。

Spheroidizing is the process of producing a structure in which the cementite is in a spheroidal distribution.If steel is heated slowly to a temperature just below the critical range and held there for a prolonged period of time, this structure will be obtained.球化是使滲碳體產生成類似球狀分布結構的工藝。如果把鋼緩慢加熱到恰好低于臨界溫度并且保持較長一段時間，就能得到這種組織結構。

The globular structure obtained gives improved machinability to the steel.This treatment is particularly useful for hypereutectoid steels that must be machined.所獲得的球狀結構改善了鋼的可切削性。此處理方法對必須機加工的過共析鋼特別有用。? Surface Hardening 表面硬化 Carburizing The oldest known method of producing a hard surface on steel is case hardening or carburizing.Iron at temperatures close to and above its critical temperature has an affinity for carbon.滲碳

最早的硬化鋼表面的方法是表面淬火或滲碳。鐵在靠近并高于其臨界溫度時對碳具有親合力。

The carbon is absorbed into the metal to form a solid solution with iron and converts the outer surface into high-carbon steel.The carbon is gradually diffused to the interior of the part.The depth of the case depends on the time and temperature of the treatment.碳被吸收進金屬與鐵形成固溶體使外表面轉變成高碳鋼。碳逐漸擴散到零件內部。滲碳層的深度取決于熱處理的時間和溫度。

Pack carburizing consists of placing the parts to be treated in a closed container with some carbonaceous material such as charcoal or coke.It is a long process and used to produce fairly thick cases of from 0.03 to 0.16 in.(0.76~4.06mm)in depth.固體滲碳的方法是將要處理的零件與木炭或焦炭這些含碳的材料一起放入密閉容器。這是一個較長的過程，用于產生深度為0.03到0.16 英寸(0.76~4.06mm)這么厚的硬化層。Steel for carburizing is usually a low-carbon steel of about 0.15% carbon that would not in itself responds appreciably to heat treatment.In the course of the process the outer layer is converted into high-carbon steel with a content ranging from 0.9% to 1.2% carbon.用于滲碳的一般是含碳量約為0.15%、本身不太適合熱處理的低碳鋼。在處理過程中外層轉化為含碳量從0.9%到1.2%的高碳鋼。

A steel with varying carbon content and, consequently, different critical temperatures requires a special heat treatment.含碳量變化的鋼具有不同的臨界溫度，因此需要特殊的熱處理。

Because there is some grain growth in the steel during the prolonged carburizing treatment, the work should be heated to the critical temperature of the core and then cooled, thus refining the core structure.The steel should then be reheated to a point above the transformation range of the case and quenched to produce a hard, fine structure.由于在較長的滲碳過程中鋼內部會有些晶粒生長，所以工件應該加熱到核心部分的臨界溫度再冷卻以細化核心部分的組織結構。然后重新加熱到高于外層轉變溫度再淬火以生成堅硬、細致的組織結構。

The lower heat-treating temperature of the case results from the fact that hypereutectoid steels are normally austenitized for hardening just above the lower critical point.A third tempering treatment may be used to reduce strains.由于恰好高于低臨界溫度通常使過共析鋼奧氏體化而硬化，所以對外層采用較低的熱處理溫度。第三次回火處理可用于減少應變。Carbonitriding Carbonitriding, sometimes known as dry cyaniding or nicarbing, is a case-hardening process in which the steel is held at a temperature above the critical range in a gaseous atmosphere from which it absorbs carbon and nitrogen.碳氮共滲

碳氮共滲，有時也稱為干法氰化或滲碳氮化，是一種表面硬化工藝。通過把鋼放在高于臨界溫度的氣體中，讓它吸收碳和氮。

Any carbon-rich gas with ammonia can be used.The wear-resistant case produced ranges from 0.003 to 0.030 inch(0.08~ 0.76mm)in thickness.An advantage of carbonitriding is that the hardenability of the case is significantly increased when nitrogen is added, permitting the use of low-cost steels.可以使用任何富碳氣體加氨氣，能生成厚度從0.003到0.030英寸(0.08~ 0.76mm)的耐磨外層。碳氮共滲的優點之一是加入氮后外層的淬透性極大增加，為使用低價鋼提供條件。Cyaniding Cyaniding, or liquid carbonitriding as it is sometimes called, is also a process that combines the absorption of carbon and nitrogen to obtain surface hardness in low-carbon steels that do not respond to ordinary heat treatment.氰化

氰化，有時稱為液體碳氮共滲，也是一種結合了吸收碳和氮來獲得表面硬度的工藝，它主要用于不適合通常熱處理的低碳鋼。

The part to be case hardened is immersed in a bath of fused sodium cyanide salts at a temperature slightly above the Ac1 range, the duration of soaking depending on the depth of the case.The part is then quenched in water or oil to obtain a hard surface.需表面硬化的零件浸沒在略高于Ac1溫度熔化的氰化鈉鹽溶液中，浸泡的持續時間取決于硬化層的深度。然后將零件在水或油中淬火。Case depths of 0.005 to 0.015in.(0.13~0.38mm)may be readily obtained by this process.Cyaniding is used principally for the treatment of small parts.通過這樣處理可以容易地獲得0.005到0.015英寸(0.13~0.38mm)的硬化深度。氰化主要用于處理小零件。Nitriding Nitriding is somewhat similar to ordinary case hardening, but it uses a different material and treatment to create the hard surface constituents.滲氮

滲氮有些類似普通表面硬化，但它采用不同的材料和處理方法來產生堅硬表面成分。In this process the metal is heated to a temperature of around 950℉(510℃)and held there for a period of time in contact with ammonia gas.Nitrogen from the gas is introduced into the steel, forming very hard nitrides that are finely dispersed through the surface metal.這種工藝中金屬加熱到約950℉(510℃)，然后與氨氣接觸一段時間。氨氣中的氮進入鋼內，形成細微分布于金屬表面又十分堅固的氮化物。Nitrogen has greater hardening ability with certain elements than with others, hence, special nitriding alloy steels have been developed.氮與某些元素的硬化能力比其它元素大，因此開發了專用的滲氮合金鋼。

Aluminum in the range of 1% to 1.5% has proved to be especially suitable in steel, in that it combines with the gas to form a very stable and hard constituent.The temperature of heating ranges from 925℉ to 1,050℉(495℃~565℃).在鋼中含鋁1%到1.5%被證明特別合適，它能與氨氣結合形成很穩定堅固的成分。其加熱溫度范圍為925℉到1,050℉(495℃~565℃)。

Liquid nitriding utilizes molten cyanide salts and, as in gas nitriding, the temperature is held below the transformation range.Liquid nitriding adds more nitrogen and less carbon than either cyaniding or carburizing in cyanide baths.液體滲氮利用熔化的氰化物鹽，就像氣體滲氮，溫度保持在低于轉化范圍內。液體滲氮時在氰化物溶液中加入比氰化及滲碳都較多的氮和較少的碳。

Case thickness of 0.001 to 0.012in.(0.03~0.30mm)is obtained, whereas for gas nitriding the case may be as thick as 0.025 in.(0.64mm).In general the uses of the two-nitriding processes are similar.液體滲氮可以獲得厚度為0.001到0.012英寸(0.03~0.30mm)的硬化層，然而氣體滲氮則能獲得厚0.025英寸(0.64mm)的硬化層。一般而言兩種滲氮方法的用途是類似的。

Nitriding develops extreme hardness in the surface of steel.This hardness ranges from 900 to 1,100 Brinell, which is considerably higher than that obtained by ordinary case hardening.滲氮在鋼表面獲得遠遠超出正常標準的硬度。其硬度范圍為900到1,100布氏硬度，這遠高于普通表面硬化所獲得的硬度。

Nitriding steels, by virtue of their alloying content, are stronger than ordinary steels and respond readily to heat treatment.It is recommended that these steels be machined and heat-treated before nitriding, because there is no scale or further work necessary after this process.由于滲氮鋼的合金比例，它們比普通鋼更強，也容易熱處理。建議對這種鋼在滲氮前先機加工和熱處理，因為滲氮后沒有剝落并不需要更多的加工。

Fortunately, the interior structure and properties are not affected appreciably by the nitriding treatment and, because no quenching is necessary, there is little tendency to warp, develop cracks, or change condition in any way.The surface effectively resists corrosive action of water, saltwater spray, alkalies, crude oil, and natural gas.值得慶幸的是由于滲氮處理一點都不影響內部結構和性能，也無需淬火，所以幾乎沒有任何產生翹曲、裂縫及變化條件的趨勢。這種表面能有效地抵御水、鹽霧、堿、原油和天然氣的腐蝕反應。

第八單元

Grinding is a manufacturing process that involves the removal of metal by employing a rotating abrasive wheel.The latter simulates a milling cutter with an extremely large number of miniature cutting edges.磨削是通過采用旋轉磨輪去除金屬的制造工藝。磨輪用非常大量的微型切削刃模仿銑刀進行切削。

Generally, grinding is considered to be a finishing process that is usually used for obtaining high-dimensional accuracy and better surface finish.Grinding can be performed on flat, cylindrical, or even internal surfaces by employing specialized machine tools, which are referred to as grinding machines.一般而言，磨削被認為是一種通常用于獲得高尺寸精度和較好表面光潔度的精加工作業。磨削通過采用被稱為磨床的特殊機床能在平面、圓柱面甚至內表面上進行。

Obviously, grinding machines differ in construction as well as capabilities, and the type to be employed is determined mainly by the geometrical shape and nature of the surface to be ground, e.g., cylindrical surfaces are ground on cylindrical grinding machines.顯然，磨床根據結構和功能的不同有所區別，使用何種形式的磨床主要取決于被磨削表面的幾何形狀和物理性質。例如，圓柱面在外圓磨床上磨削。? Type of Grinding Operations 磨削作業的類型

1.Surface grinding.As the name surface grinding suggests, this operation involves grinding of flat or plane surfaces.Fig.8.1 indicates the two possible variations, either a horizontal or vertical machine spindle.1.表面磨削：就像其名稱暗示的那樣，表面磨削和平面磨削直接有關。圖8.1表示了兩種可能的變化：臥式磨床主軸或立式磨床主軸。

In the first case(horizontal spindle), the machine usually has a planer-type reciprocating table on which the workpiece is held.However, grinding machines with vertical spindles can have either a planer type table like that of the horizontal-spindle machine or a rotating worktable.在第一種情況(臥式主軸)，臥式磨床通常具有安裝工件的刨床式往復工作臺。而立式主軸磨床既可以像臥式主軸磨床那樣具有刨床式工作臺也可以具有旋轉工作臺。

Also, the grinding action in this case is achieved by the end face of the grinding wheel(Fig.8.1b), contrary to the case of horizontal-spindle machines, where the workpieces ground by the periphery of the grinding wheel.而且在這種情況下，磨削動作是通過砂輪端面完成的(圖8.1b)，這與通過砂輪周邊磨削工件的臥式主軸磨床正好相反。

Fig.8.1a and b also indicate the equations to be used for estimating the different parameters of the grinding operation, such as the machining time and the rate of metal removal.圖8.1a和b同時簡述了用于估計諸如加工時間和金屬去除率之類的磨削作業不同參數的方程式。During the surface-grinding operations, heavy workpieces are either held in fixtures or clamped on the machine table by strap clamps and the like, whereas smaller workpieces are usually held by magnetic chucks.在平面磨削時，重的工件用夾具固定或用壓板等夾緊在磨床工作臺上，而小的工件則通常是用電磁卡盤固定的。

2.Cylindrical grinding.In cylindrical grinding, the workpiece is held between centers during the grinding operation, and the wheel rotation is the source and cause for the rotary cutting motion, as shown in Fig.8.2.In fact, cylindrical grinding can be carried out by employing any of the following methods: 2.圓柱面磨削：在圓柱面磨削中，作業時工件支撐在兩頂尖之間，砂輪轉動是導致回轉切削運動的動力源，如圖8.2所示。實際上，圓柱面磨削能通過采用下列任意方法來實現：(1)The transverse method, in which both the grinding wheel and the workpiece rotate and longitudinal linear feed is applied to enable grinding of the whole length.The depth of cut is adjusted by the cross feed of the grinding wheel into the workpiece.(1)橫向方法：這種方法中砂輪與工件均旋轉且采用線性縱向進給以保證能磨削整個長度。切削深度通過改變砂輪對工件的橫向進給來進行調整。

(2)The plunge-cut method, in which grinding is achieved through the cross feed of the grinding wheel and no axial feed is applied.As you can see, this method can be applied only when the surface to be ground is shorter than the width of the grinding wheel used.(2)插入-切削方法：這種方法通過砂輪的橫向進給完成磨削而不采用軸向進給。正如料想的那樣，這種方法只在要磨削表面比所用砂輪寬度短時才使用。(3)The full-depth method, which is similar to the transverse method except that the grinding allowance is removed in a single pass.This method is usually recommended when grinding short rigid shafts.(3)全深度方法：這種方法除了一次加工就能去除磨削余量外其它與橫向方法相同。這種方法通常在磨削較短剛性軸時推薦使用。

Internal grinding.Internal grinding is employed for grinding relatively short holes, as shown in Fig.8.3.The workpiece is held in a chuck or a special fixture.Both the grinding wheel and the workpiece rotate during the operation and feed is applied in the longitudinal direction.內表面磨削：內表面磨削用于相對較短的孔，如圖8.3所示。工件安裝在卡盤或特殊夾具上。作業時砂輪和工件都回轉并且采用縱向進給。

Any desired depth of cut can be obtained by the cross feed of the grinding wheel.A variation from this type is planetary internal grinding, which is recommended for heavy workpieces that cannot be held in chucks.通過砂輪的橫向進給能得到任意所需的切削深度。這種方法的一個變體是行星式內表面磨削，當工件較重不能用卡盤固定時推薦使用。

In that case, the grinding wheel not only spins around its own axis but also rotates around the centerline of the hole that is being ground.在這種情況下，砂輪不但繞自身軸線回轉，同時還繞被磨削孔的中心線旋轉。

Centerless grinding.Centerless grinding involves passing a cylindrical workpiece, which is supported by a rest blade, between two wheels, i.e., the grinding wheel and the regulating or feed wheel.無心磨削：無心磨削用于加工圓柱形工件，工件由托板支撐，在兩輪即砂輪和調節或進給輪之間通過去。The grinding wheel does the actual grinding, while the regulating wheel is responsible for rotating the workpiece as well as generating the longitudinal feed.This is possible because of the frictional characteristics of that wheel, which is usually made of rubber-bonded abrasive.砂輪完成實際磨削，而調節輪負責旋轉工件和產生縱向進給。由于調節輪通常用橡膠粘結的磨料制成，其摩擦特性使這成為可能。

As can be seen in Fig.8.4, the axis of the regulating wheel is tilted at a slight angle with the axis of the grinding wheel.Consequently, the peripheral velocity of the regulating wheel can be resolved into two components, namely, workpiece rotational speed and longitudinal feed.正如在圖8.4中所看到的那樣，調節輪的軸與砂輪軸傾斜一個微小角度。因此調節輪的圓周速度可以分解為兩個分量，即工件回轉速度和縱向進給。These can be given by the following equations: Vworkpiece＝Vregulating wheel×cosα Axial feed＝Vregulating wheel×c×sinα

Where c is a constant coefficient to account for the slip between the workpiece and the regulating wheel(c=0.94~0.98).其值可由下列公式給出：

V工件＝V調節輪×cosα

軸向進給＝V調節輪×c×sinα 式中c是考慮工件和調節輪之間滑動的恒定系數(c=0.94~0.98)。

The velocity of the regulating wheel is controllable and is used to achieve any desired rotational speed of the workpiece.The angleαis usually taken from 1°to 5°and the larger the angle, the larger the longitudinal feed would be.調節輪的速度是可控的并被用于實現工件任意所需的轉動速度。α角通常取1到 5°，這角度越大則縱向進給也將越大。

Whenαis taken as 0°, i.e., the two axes of the grinding and regulating wheels are parallel, there is no longitudinal feed of the workpiece.當α取0°時，即砂輪和調節輪軸線平行時，則工件沒有縱向進給。? Grinding Wheels 砂輪

Grinding wheels are composed of abrasive grains having similar size and a binder.The actual grinding process is performed by the abrasive grains.Pores between the grains within the binder enable the grains to act as separate single-point cutting tools.砂輪由具有相近尺寸的磨料顆粒和粘合劑組成。實際磨削作業由磨粒完成。在粘合劑中磨粒之間的孔隙使磨粒能象獨立的單刃切削刀具一樣工作。

These pores also provide space for the generated chips, thus preventing the wheel from clogging.In addition, pores assist the easy flow of coolants to enable efficient and prompt removal of the heat generated during the grinding process.這些孔隙同時還為產生的切屑提供空間以防砂輪堵塞。另外孔隙幫助冷卻液容易流動，從而使在磨削作業中產生的熱量能有效而迅速地散發。Grinding wheels are identified based on their shape and size, kind of abrasive, grain size, binder, grade(hardness), and structure.砂輪根據它們的形狀和尺寸、磨料的類型、磨粒的大小、粘合劑、等級(硬度)和結構組織來分類。

Shape and size of grinding wheels.Grinding wheels differ in shape and size, depending upon the purpose for which they are to be used.Various shapes are shown in Fig.8.5 and include the following types: 砂輪的形狀和尺寸：根據砂輪的用途，它們的形狀和尺寸是不同的。各種形狀如圖8.5所示，其中包括：

1)Straight wheels used for surface, cylindrical, internal, and centerless grinding.2)Bevelled-face or tapered wheels used for grinding threads, gear teeth, and the like.3)Straight recessed wheels for cylindrical grinding and facing.1)用于表面、圓柱面、內部和無心磨削的直輪。2)用于磨削螺紋、齒輪輪齒之類的斜面或錐形輪。3)用于圓柱面和端面磨削的直凹輪。

4)Abrasive disks for cutoff and slotting operations.(thickness 0.02 up to 0.2in.(0.5 to 5mm)).5)Cylinders, straight cups, and flaring cups are used for surface grinding with the end face of the wheel.4)用于切斷和開槽作業的砂輪片(其厚度從0.02到0.2英寸(0.5到5毫米))。5)用其端面進行表面磨削的圓柱、直杯及外展杯狀砂輪。

The main dimensions of a grinding wheel are the outside diameter D, the bore diameter d, and the height H.These dimensions vary widely, depending upon the grinding process for which the wheel is to be used.砂輪的主要尺寸有外徑D、孔徑d和厚度H。根據采用砂輪的磨削工藝，這些尺寸變化很大。

Kind of abrasive.Grinding wheels can be made of natural abrasives such as quartz, emery, and corundum or of industrially prepared chemical compounds such as aluminum oxide or silicon carbide(known as carborundum).磨料的類型：砂輪可以由象石英、金剛砂、剛玉之類的自然磨料制成，或者由象氧化鋁或碳化硅(也稱人造金剛砂)之類的工業制備的化學化合物制成。

Generally, silicon carbide grinding wheels are used when grinding low-tensile-strength materials like cast iron, whereas aluminum oxide wheels are employed for grinding high-strength metals such as alloy steel, hardened steel, and the like.當磨削象鑄鐵類低拉伸強度材料時，一般采用碳化硅砂輪，而磨削合金鋼、淬火鋼等高強度金屬則要用氧化鋁砂輪。

Grain size of abrasive used.As you may expect, the grain size of the abrasive particles of the wheel plays a fundamental role in determining the quality of ground surface obtained.所用磨粒的尺寸：正如料想的那樣，砂輪磨粒的尺寸對決定所得磨削表面的質量起著根本的作用。

The finer the grains, the smoother the ground surface is.Therefore, coarse-grained grinding wheels are used for roughing operations, whereas fine-grained wheels are employed in final finishing operations.磨粒越細，磨削表面越光滑。所以，粗粒砂輪用于粗加工，而細粒砂輪則用于最后精加工。The grade of the bond.The grade of the bond is actually an indication of the resistance of the bond to pulling off the abrasive grains from the grinding wheel.Generally, wheels having hard grades are used for grinding soft materials and vice versa.粘結體的等級：粘結體的等級實際上是其抵抗將磨粒從砂輪上拉脫的指標。一般而言，具有較硬等級的砂輪用于磨削較軟材料，反之亦然。

If a hard-grade wheel were to be used for grinding a hard material, the dull grains would not be pulled off from the bond quickly enough, thus impeding the self-dressing process of the surface of the wheel and finally resulting in clogging of the wheel and burns on the ground surface.如果較硬等級的砂輪用于磨削較硬材料，磨鈍的磨粒將不能足夠快地脫離粘結體，這會妨礙砂輪表面的自修復，最終導致砂輪的堵塞并在被磨表面留下灼斑。

In fact, the cutting properties of all grinding wheels must be restored periodically by dressing with a cemented carbide roller or a diamond tool to give the wheel the exact desired shape and remove all worn abrasive grains.實際上，所有砂輪的磨削性能都必須定期地通過使用硬質合金滾輪或金剛石修整器修整而被恢復，以求很準確地把砂輪加工成要求的形狀，并去除已磨鈍的磨粒。

Structure.Structure refers to the amount of void space between the abrasive grains.When grinding softer metals, larger void space are needed to facilitate the flow of the removed chips.結構組織：結構組織與磨粒間的空隙量有關。當磨削較軟金屬時，需要較大的空隙以便去除切屑的流動。

The binder.Abrasive particles are bonded together in many different ways.These include bond, silicate, rubber, resinoid, shellac, and oxychloride.Nevertheless, the bond is the most commonly used one.粘合劑：磨?？捎枚喾N不同方法粘結在一起。其中包括粘合劑、硅酸鹽、橡膠、樹脂、蟲膠和氯氧化物。然而，粘合劑是最常用的。

In fact, the standard marking system is employed for distinguishing grinding wheels, by providing all the preceding parameters in a specific sequence.在實際生產中，為了區分砂輪采用標準標注系統，通過用一特定順序將所有上述參數都表示出來。

第十一單元

? The Lathe and Its Construction 車床及其結構

A lathe is a machine tool used primarily for producing surfaces of revolution and flat edges.車床是主要用于生成旋轉表面和平整邊緣的機床。

Based on their purpose, construction, number of tools that can simultaneously be mounted, and degree of automation, lathes-or, more accurately, lathe-type machine tools can be classified as follows: 根據它們的使用目的、結構、能同時被安裝刀具的數量和自動化的程度，車床—或更確切地說是車床類的機床，可以被分成以下幾類：

(1)Engine lathes(2)Toolroom lathes(3)Turret lathes(4)Vertical turning and boring mills(5)Automatic lathes(6)Special-purpose lathes(1)普通車床(2)萬能車床(3)轉塔車床(4)立式車床(5)自動車床(6)特殊車床

In spite of that diversity of lathe-type machine tools, they all have common features with respect to construction and principle of operation.These features can best be illustrated by considering the commonly used representative type, the engine lathe.Following is a description of each of the main elements of an engine lathe, which is shown in Fig.11.1.雖然車床類的機床多種多樣，但它們在結構和操作原理上具有共同特性。這些特性可以通過普通車床這一最常用的代表性類型來最好地說明。下面是關于圖11.1所示普通車床的主要部分的描述。

Lathe bed.The lathe bed is the main frame, involving a horizontal beam on two vertical supports.It is usually made of grey or nodular cast iron to damp vibrations and is made by casting.車床床身：車床床身是包含了在兩個垂直支柱上水平橫梁的主骨架。為減振它一般由灰鑄鐵或球墨鑄鐵鑄造而成。

It has guideways to allow the carriage to slide easily lengthwise.The height of the lathe bed should be appropriate to enable the technician to do his or her job easily and comfortably.它上面有能讓大拖板輕易縱向滑動的導軌。車床床身的高度應適當以讓技師容易而舒適地工作。

Headstock.The headstock is fixed at the left hand side of the lathe bed and includes the spindle whose axis is parallel to the guideways(the slide surface of the bed).The spindle is driven through the gearbox, which is housed within the headstock.主軸箱：主軸箱固定在車床床身的左側，它包括軸線平行于導軌的主軸。主軸通過裝在主軸箱內的齒輪箱驅動。The function of the gearbox is to provide a number of different spindle speeds(usually 6 up to 18 speeds).Some modern lathes have headstocks with infinitely variable spindle speeds, which employ frictional ,electrical ,or hydraulic drives.齒輪箱的功能是給主軸提供若干不同的速度(通常是6到18速)。有些現代車床具有采用摩擦、電力或液壓驅動的無級調速主軸箱。The spindle is always hollow, i.e., it has a through hole extending lengthwise.Bar stocks can be fed through that hole if continuous production is adopted.主軸往往是中空的，即縱向有一通孔。如果采取連續生產，棒料能通過此孔進給。Also, that hole has a tapered surface to allow mounting a plain lathe center.The outer surface of the spindle is threaded to allow mounting of a chuck, a face plate, or the like.同時，此孔為錐形表面可以安裝普通車床頂尖。主軸外表面是螺紋可以安裝卡盤、花盤或類似的裝置。

Tailstock.The tailstock assembly consists basically of three parts, its lower base, an intermediate part, and the quill.The lower base is a casting that can slide on the lathe bed along the guideways, and it has a clamping device to enable locking the entire tailstock at any desired location, depending upon the length of the workpiece.尾架：尾架總成基本包括三部分，底座、尾架體和套筒軸。底座是能在車床床身上沿導軌滑動的鑄件，它有一定位裝置能讓整個尾架根據工件長度鎖定在任何需要位置。The intermediate part is a casting that can be moved transversely to enable alignment of the axis of the tailstock with that of the headstock.The third part, the quill, is a hardened steel tube, which can be moved longitudinally in and out of the intermediate part as required.尾架體為一能橫向運動的鑄件，它可以調整尾架軸線與主軸箱軸線成一直線。第三部分，套筒軸是一淬硬鋼管，它能根據需要在尾架體中縱向進出移動。

This is achieved through the use of a handwheel and a screw, around which a nut fixed to the quill is engaged.The hole in the open side of the quill is tapered to enable mounting of lathe centers or other tools like twist drills or boring bars.The quill can be locked at any point along its travel path by means of a clamping device.這通過使用手輪和螺桿來達到，與螺桿嚙合的是一固接在套筒軸上的螺母。套筒軸開口端的孔是錐形的，能安裝車床頂尖或諸如麻花鉆和鏜桿之類的工具。套筒軸通過定位裝置能沿著它的移動路徑被鎖定在任何點。The carriage.The main function of the carriage is mounting of the cutting tools and generating longitudinal and/or cross feeds.It is actually an H-shaped block that slides on the lathe bed between the headstock and tailstock while being guided by the V-shaped guideways of the bed.大拖板：大拖板的主要功能是安裝刀具和產生縱向和/或橫向進給。它實際上是一由車床床身V形導軌引導的、能在車床床身主軸箱和尾架之間滑動的H形滑塊。

The carriage can be moved either manually or mechanically by means of the apron and either the feed rod or the lead screw.大拖板能手動或者通過溜板箱和光桿(進給桿)或絲桿(引導螺桿)機動。

When cutting screw threads, power is provided to the gearbox of the apron by the lead screw.In all other turning operations, it is the feed rod that drives the carriage.The lead screw goes through a pair of half nuts, which are fixed to the rear of the apron.在切削螺旋時，動力通過絲桿提供給溜板箱上的齒輪箱。在其余車削作業中，都由光桿驅動大拖板。絲桿穿過一對固定在溜板箱后部的剖分螺母。

When actuating a certain lever, the half nuts are clamped together and engage with the rotating lead screw as a single nut, which is fed, together with the carriage, along the bed.When the lever is disengaged, the half nuts are released and the carriage stops.當開動特定操作桿時，剖分螺母夾在一起作為單個螺母與旋轉的絲桿嚙合，并帶動拖板沿著床身提供進給。當操作桿脫離時，剖分螺母釋放同時大拖板停止運動。

On the other hand, when the feed rod is used, it supplies power to the apron through a worm gear.The latter is keyed to the feed rod and travels with the apron along the feed rod, which has a keyway extending to cover its whole length.另一方面，當使用光桿時則通過蝸輪給溜板箱提供動力。蝸輪用鍵連接在光桿上，并與溜板箱一起沿光桿運動，光桿全長范圍開有鍵槽。

A modern lathe usually has a quick-change gearbox located under the headstock and driven from the spindle through a train of gears.It is connected to both the feed rod and the lead screw and enables selecting a variety of feeds easily and rapidly by simply shifting the appropriate levers.現代車床一般在主軸箱下裝備快速變換齒輪箱，通過一系列齒輪由主軸驅動。它與光桿和絲桿連接，能容易并快速地通過簡單轉換適當的操作桿選擇各種進給。

The quick-change gearbox is employed in plain turning, facing and thread cutting operations.Since that gearbox is linked to the spindle, the distance that the apron(and the cuttingtool)travels for each revolution of the spindle can be controlled and is referred to as the feed.快速變換齒輪箱可用于普通車削、端面切削和螺旋切削作業中。由于這種齒輪箱與主軸相連，主軸每轉一圈溜板箱(和切削刀具)運動的距離能被控制，這距離就可以被認為是進給。? Lathe Cutting Tools 車床切削刀具

The shape and geometry of the lathe tools depend upon the purpose for which they are employed.車床刀具的形狀和幾何參數取決于它們的使用目的。

Turning tools can be classified into two main groups, namely, external cutting tools and internal cutting tools.Each of these two groups include the following types of tools: 車削刀具可以分為兩個主要組別，即外部切削刀具和內部切削刀具。這兩組中的每一組都包括以下類型刀具： Turning tools.Turning tools can be either finishing or rough turning tools.Rough turning tools have small nose radii and are employed when deep cuts are made.車削刀具：車削刀具可以是精車刀具或粗車刀具。粗車刀具刀尖半徑較小，用于深切削。

On the other hand, finishing tools have larger nose radii and are used for obtaining the final required dimensions with good surface finish by making slight depths of cut.Rough turning tools can be right-hand or left-hand types, depending upon the direction of feed.They can have straight, bent, or offset shanks.而精車刀具刀尖半徑較大，用于通過微量進刀深度來獲得具有較好表面光潔度的最終所需尺寸。粗車刀具按其進給方向可以是右手型的或是左手型的。它們可以有直的、彎的或偏置的刀桿。

Facing tools.Facing tools are employed in facing operations for machining plane side or end surfaces.There are tools for machining left-hand-side surfaces and tools for right-hand-side surfaces.Those side surfaces are generated through the use of the cross feed, contrary to turning operations, where the usual longitudinal feed is used.端面刀具：端面刀具用在端面作業中加工平板側面或端部表面，也有加工左右側表面之分。與一般采用縱向進給的車削作業相反，那些側表面通過采用橫向進給產生。

Cutoff tools.Cutoff tools, which are sometimes called parting tools, serve to separate the workpiece into parts and/or machine external annular grooves.切斷刀具：切斷刀具，有時也稱為分割刀具，用于將工件分割成若干部分和/或加工外部環形槽。

Thread-cutting tools.Thread-cutting tools have either triangular, square, or trapezoidal cutting edges, depending upon the cross section of the desired thread.Also, the plane angles of these tools must always be identical to those of the thread forms.螺紋切削刀具：螺紋切削刀具根據所需螺紋的橫截面，有三角形的、矩形的或梯形的切削刃。同時，這些刀具的平面角必須始終與螺紋形狀的平面角保持一致。

Thread-cutting tools have straight shanks for external thread cutting and are of the bent-shank type when cutting internal threads.車外螺紋的螺紋切削刀具為直刀桿，而車內螺紋的螺紋切削刀具則是彎刀桿。

Form tools.Form tools have edges especially manufactured to take a certain form, which is opposite to the desired shape of the machined workpiece.成形刀具：成形刀具有專門制成特定形狀的刀刃，這種刀刃形狀與被加工工件所需外形正好相反。An HSS tool is usually made in the form of a single piece, contrary to cemented carbides or ceramic, which are made in the form of tips.The latter are brazed or mechanically fastened to steel shanks．

高速鋼刀具通常以單件形式制造，而硬質合金或陶瓷刀具則以刀尖形式制造。后者用銅焊或機械方法固定于鋼質刀桿上。

Fig.11.2 indicates an arrangement of this latter type, which includes the carbide tip, the chip breaker, the pad, the clamping screw(with a washer and a nut), and the shank.圖11.2所示為機械式固定布置方式，它包括了硬質合金刀尖、斷屑槽、襯墊、卡裝螺桿(帶有墊圈和螺母)及刀桿。

As the name suggests, the function of the chip breaker is to break long chips every now and then, thus preventing the formation of very long twisted ribbons that may cause problems during the machining operation.顧名思義，斷屑槽的功能就是不時地折斷長切屑，以防形成很長的可能會在機加工操作中引起問題的纏繞切屑條。

The carbide tips(or ceramic tips)can have different shapes, depending upon the machining operations for which they are to be employed.The tips can either be solid or with a central through hole, depending on whether brazing or mechanical clamping is employed for mounting the tip on the shank.硬質合金刀尖(或陶瓷刀尖)根據采用它們的機加工操作，可以有不同的形狀。根據將刀尖裝配在刀桿上是通過用銅焊還是機械卡裝，刀尖可以是實心的或是帶有中心通孔的。? Lathe Operations 車床操作

In the following section, we discuss the various machining operations that can be performed on a conventional engine lathe.在下面這節中，要討論的是能在傳統普通車床上進行的各種機加工作業。

It must be borne in mind, however, that modern computerized numerically controlled lathes have more capabilities and can do other operations, such as contouring, for example.Following are conventional lathe operations.然而，必須記住現代計算機數控車床具有更多的功能并且可以進行其它操作，例如仿型。下面是傳統車床的操作。

Cylindrical turning.Cylindrical turning is the simplest and the most common of all lathe operations.A single full turn of the workpiece generates a circle whose center falls on the lathe axis;this motion is then reproduced numerous times as a result of the axial feed motion of the tool.圓柱面車削：圓柱面車削是所有車床操作中最簡單也是最普通的。工件旋轉一整圈產生一個圓心落在車床主軸上的圓；由于刀具的軸向進給運動這種動作重復許多次。The resulting machining marks are, therefore, a helix having a very small pitch, which is equal to the feed.Consequently, the machined surface is always cylindrical.所以，由此產生的機加工痕跡是一條具有很小節距的螺旋線，該節距等于進給。因此機加工表面始終是圓柱形的。

The axial feed is provided by the carriage or the compound rest, either manually or automatically, whereas the depth of cut is controlled by the cross slide.軸向進給通過大拖板或復式刀架手動或自動提供，然而切削深度則由橫向滑板控制。In roughing cuts, it is recommended that large depths of cuts(up to 0.25in.or 6mm, depending upon the workpiece material)and smaller feeds would be used.On the other hand, very fine feeds, smaller depths of cut(less than 0.05in, or 0.4mm), and high cutting speeds are preferred for finishing cuts.粗車中，推薦使用較大切削深度(根據工件材料可達0.25英寸或6毫米)和較小進給。另一方面，精車則最好采用很小的進給、較小的切削深度(小于0.05英寸或0.4毫米)和較高的切削速度。

Facing.The result of a facing operation is a flat surface that is either the whole end surface of the workpiece or an annular intermediate surface like a shoulder.During a facing operation, feed is provided by the cross slide, whereas the depth of cut is controlled by the carriage or compound rest.端面車削：端面車削操作的結果是將工件整個端部表面或者像軸肩之類的中間環形表面加工平整。在端面車削操作中，進給由橫向滑板提供，而切削深度則通過大拖板或復式刀架控制。

Facing can be carried out either from the periphery inward or from the center of the workpiece outward.It is obvious that the machining marks in both cases take the form of a spiral.端面車削既可以從外表面向內切削也可以從工件中心往外切削。很明顯在這兩種情況下機加工痕跡都是螺線形式。

Usually, it is preferred to clamp the carriage during a facing operation, since the cutting force tends to push the tool(and, of course, the whole carriage)away from the workpiece.In most facing operations, the workpiece is held in a chuck or on a face plate.通常在端面車削作業時習慣于采用夾住大拖板，這是因為切削力傾向于將刀具(當然包括整個大拖板)推離工件。在大多數端面車削作業中，工件被支撐在卡盤或花盤上。

Groove cutting.In cut-off and groove-cutting operations, only cross feed of the tool is employed.The cut-off and grooving tools, which were previously discussed, are employed.開槽：在切斷和開槽操作中，刀具只有橫向進給。要采用前面已經討論過的切斷和開槽刀具。

Boring and internal turning.Boring and internal turning are performed on the internal surfaces by a boring bar or suitable internal cutting tools.If the initial workpiece is solid, a drilling operation must be performed first.The drilling tool is held in the tailstock, and the latter is then fed against the workpiece.鏜孔和內部車削：鏜孔和內部車削通過鏜桿或合適的內部切削刀具在內表面進行。如果初始工件是實心的，則必須首先進行鉆孔作業。鉆孔刀具安裝在尾架上，然后對著工件進給。

Taper turning.Taper turning is achieved by driving the tool in a direction that is not parallel to the lathe axis but inclined to it with an angle that is equal to the desired angle of the taper.Following are the different methods used in taper-turning practice: 錐面車削：錐面車削通過沿著與車床主軸不平行而傾斜成一個等于錐面所需角度的方向進刀來實現。下面是在實際錐面車削中采用的不同方法：

(1)Rotating the disc of the compound rest with an angle equal to half the apex angle of the cone.Feed is manually provided by cranking the handle of the compound rest.This method is recommended for taper turning of external and internal surfaces when the taper angle is relatively large.(1)將復式刀架盤旋轉一個等于圓錐體頂角一半的角度。通過搖動復式刀架操縱柄手動提供進給。當錐角相對較大時切削外錐面和內錐面推薦使用這種方法。(2)Employing special form tools for external, very short, conical surfaces.The width of the workpiece must be slightly smaller than that of the tool, and the workpiece is usually held in a chuck or clamped on a face plate.In this case, only the cross feed is used during the machining process and the carriage is clamped to the machine bed.(2)對很短的外錐面采用特殊的成型刀具。工件的寬度必須略小于刀具的寬度，并且工件通常由卡盤支撐或夾緊在花盤上。在這種情況下，機加工作業時只有橫向進給而大拖板則夾緊在床身上。

(3)Offsetting the tailstock center.This method is employed for external taper turning of long workpieces that are required to have small taper angles(less than 8°).The workpiece is mounted between the two centers;then the tailstock center is shifted a distance S in the direction normal to the lathe axis.(3)偏移尾架頂尖。對需要較小錐角(小于8°)的較長工件外錐面車削采用這種方法。工件安裝于兩頂尖之間；然后將尾架頂尖朝垂直于車床主軸方向移動一距離S。

(4)Using the taper-turning attachment.This method is used for turning very long workpieces, when the length is larger than the whole stroke of the compound rest.The procedure followed in such cases involves complete disengagement of the cross slide from the carriage, which is then guided by the taper-turning attachment.(4)采用錐面車削附加裝置。這種方法用于車削很長的工件，其長度大于復式刀架的整個行程。在這種場合下要遵循的步驟是將橫向滑板完全脫離大拖板，然后通過錐面車削附加裝置進行引導。

During this process, the automatic axial feed can be used as usual.This method is recommended for very long workpieces with a small cone angle, i.e., 8°through 10°.在此作業中，能照常使用自動軸向進給。對具有較小錐角(即8°到10°)的很長工件推薦采用這種方法。

Thread cutting.When performing thread cutting, the axial feed must be kept at a constant rate, which is dependent upon the rotational speed(rpm)of the workpiece.The relationship between both is determined primarily by the desired pitch of the thread to be cut.螺紋切削：在螺紋切削作業時，軸向進給必須保持恒定速率，這取決于工件的轉速(rpm)。兩者之間的關系基本上由被切削螺紋所需的節距決定。

As previously mentioned, the axial feed is automatically generated when cutting a thread by means of the lead screw, which drives the carriage.When the lead screw rotates a single revolution, the carriage travels a distance equal to the pitch of the lead screw.如前所述，當依靠驅動大拖板的絲桿切削螺紋時軸向進給是自動產生的。絲桿旋轉一圈，大拖板就行進等于絲桿節距的一段距離。Consequently, if the rotational speed of the lead screw is equal to that of the spindle(i.e., that of the workpiece), the pitch of the resulting cut thread is exactly equal to that of the lead screw.因此如果絲桿的旋轉速度等于心軸的轉速(即工件的轉速)，生成切削螺紋的節距就正好等于絲桿的節距。

The pitch of the resulting thread being cut therefore always depends upon the ratio of the rotational speeds of the lead screw and the spindle: Pitch of the lead screw/ Desired pitch of workpiece=rpm of the workpiece/rpm of lead screw=spindle-to-carriage gearing ratio.所以被切削生成螺紋的節距總是取決于絲桿和心軸的轉速比：絲桿的節距/工件所需節距=工件轉速/絲桿轉速=心軸到大拖板的傳動比。This equation is useful in determining the kinematic linkage between the lathe spindle and the lead screw and enables proper selection of the gear train between them.這公式在決定車床心軸和絲桿之間的運動學關系時很有用，并且提供了正確挑選它們之間輪系的方法。

In thread cutting operations, the workpiece can either be held in the chuck or mounted between the two lathe centers for relatively long workpieces.The form of the tool used must exactly coincide with the profile of the thread to be cut, i.e., triangular tools must be used for triangular threads, and so on.在螺紋切削作業中，工件既能支撐于卡盤中，對相對較長的工件也能安裝在兩個車床頂尖之間。使用的刀具外形必須正好與要切削螺紋的輪廓一致，即三角形刀具必須用于三角形螺紋等等。

Knurling.Knurling is mainly a forming operation in which no chips are produced.It involves pressing two hardened rolls with rough filelike surfaces against the rotating workpiece to cause plastic deformation of the workpiece metal.滾花：滾花主要是一種不產生切屑的成型操作。它使用兩個帶有粗銼式表面的淬火滾輪壓在旋轉的工件上使工件金屬產生塑性變形。

Knurling is carried out to produce rough, cylindrical(or conical)surfaces, which are usually used as handles.Sometimes, surfaces are knurled just for the sake of decoration;there are different types of patterns of knurls from which to choose.滾花用于生成粗糙的圓柱(或圓錐)面，通常用來作手柄。有時表面滾花只為裝飾之故；有不同的滾花圖案類型可供選擇。? Cutting Speeds and Feed 切削速度和進給

The cutting speed, which is usually given in surface feet per minute(SFM), is the number of feet traveled in the circumferential direction by a given point on the surface(being cut)of the workpiece in 1 minute.切削速度，通常用每分鐘表面英尺給出，就是一分鐘內工件(被切削)表面給定點在圓周方向上行進的英尺數。

The relationship between the surface speed and rpm can be given by the following equation: SFM=πDN Where D=the diameter of the workpiece in feet N=the rpm 表面速度與轉速之間的關系可以用下式給出： SFM=πDN 式中

D=用英尺表示的工件直徑 N=轉速

The surface cutting speed is dependant primarily upon the material being machined as well as the material of the cutting tool and can be obtained from handbooks, information provided by cutting tool manufacturers, and the like.表面切削速度主要由被切削材料和切削刀具材料決定，可以從手冊、切削刀具生產商提供的資料及類似的東西上查取。Generally, the SFM is taken as 100 when machining cold-rolled or mild steel, as 50 when machining tougher metals, and as 200 when machining softer materials.For aluminum, the SFM is usually taken as 400 or above.There are also other variables that affect the optimal value of the surface cutting speed.一般而言，SFM當機加工冷軋或低碳鋼時取100，機加工較堅韌的金屬時取50，而機加工較軟材料時取200。對鋁而言，SFM通?？扇?00以上。也還存在其它一些變量影響表面切削速度的最佳值。

These include the tool geometry, the type of lubricant or coolant, the feed, and the depth of cut.As soon as the cutting speed is decided upon, the rotational speed(rpm)of the spindle can be obtained as follows: N=SFM/(πD)其中包括刀具形狀、潤滑劑或冷卻液的類型、進給和切削深度。切削速度一旦確定，心軸轉速(rpm)就能按下式得到： N=SFM/(πD)The selection of a suitable feed depends upon many factors, such as the required surface finish, the depth of cut, and the geometry of the tool used.Finer feeds produce better surface finish, whereas higher feeds reduce the machining time during which the tool is in direct contact with the workpiece.合適進給的選擇取決于許多因素，例如所需表面光潔度、切削深度和所用刀具的幾何形狀。進給越小生成的光潔度越好，而在刀具與工件直接接觸時進給越大則可以減少機加工時間。

Therefore, it is generally recommended to use high feeds for roughing operations and finer feeds for finishing operations.Again, recommended values for feeds, which can be taken as guidelines, are found in handbooks and in information booklets provided by cutting tool manufacturers.所以對粗車一般推薦使用較大進給，而精車則用較小進給。再者，作為指導方針的進給推薦值可以從手冊和切削刀具生產商提供的資料小冊子上找到。

第五篇：機械圖紙英語翻譯

機加工圖紙有英語看不懂？不怕！史上最全翻譯都在這里了

機械圖紙英語翻譯

ALL WELDS CONTINUOUS UNLESS OTHERWISE STATED 未注焊縫均為連續焊

ALL WELDS 3mm FILLET UNLESS OTHERWISE STATED 未注焊角高3mm.ALL UNSPECIFIED RADI-R3 未注圓角R3 REMOVE ALL BURRS AND SHARP EDGES 棱角倒鈍 CHANNEL 槽鋼 RSA 708 角鋼 70X70X8 M30X1.5 pitch M30X1.5的錐螺紋 Tackweld 點焊

OD 1/4“ outside dimension 1/4”的縮寫 外徑直1/4“ 75 CRS 尺寸為75 材質為冷軋鋼板 410 OPENING REF 410 開口參考尺寸 40 REF 尺寸為40,參考值 2.5” BSP 2.5” 圓錐管螺紋

2.5“ BSPT HEXAGON 2.5” 六角圓錐管螺紋(即對絲)30x2.5 FLAT BAR 30X2.5 扁鋼 TYP 2 POSNS 2處 TOTAL COILS APROX.9 WORKING COILS APROX.RIGHT HAND WOUND ONLY,END COILS SQUARE TO TOUCH.總圈數約11圈；工作圈數約9圈；右旋；彈簧的端部磨平以便于接觸.(此為彈簧技術說明)

FEMALE: 內扣(母扣)MALE: 外扣(公扣)偏心軸 eccentric shaft 銷軸 PIN 開口銷 COTTER PIN 螺桿 screw 緊定螺釘 SET SCREW 圓螺母 ROUND NUT 內六角螺釘 SOCKET HEAD CAP SCREW 六角螺釘 HEX HD SETSCREW 六角螺栓 HEX HD BOLT 擋圈 closing ring 彈性擋圈 circlip 軸承隔套 distance sleeve of axletree 軸承 axletree 深溝球軸承 DEEP GROOVE BALL BEARING 無扣長 non-buckle longth 彈簧 SPRING 吊環螺釘 LIFTING EYE BOLT 開槽盤頭螺釘 SLOTTED PAN HEAD SCREW 圓錐滾子軸承 TAPERED ROLLER BEARING 推力球軸承THRUST BALL BEARING平鍵 FLAT KEY 彈簧墊圈 SINGLE COIL SPRING WASHER平墊圈 FLAT WASHER 螺母 FULL NYLOCK NUT 圓螺母 ROUND NUT REMOVE ALL BURRS AND SHARP EDGES 所有尖角/棱角倒角并去毛刺

REF 為測量的參考尺寸

OD 1/4’ outside dimension 1/4”的縮寫 外徑直1/4’------->應該為：外徑值1/4“ 75 CRS 尺75 材質為冷軋鋼板------->應該為：尺寸75 材質為冷軋鋼板

ACCESS Accessory 附件 ADJ Adjustable,Adjust 調整 ADPT Adapter 使適應 ADV Advance 提前 AL Aluminum 鋁 ALLOW Allowance 允許 LT Alternate 改變 ALY Alloy 合金 AMT Amout 數量 ANL Anneal 鍛煉

ANSL Amer Natl Stds Institute APPROX Approximate 大約 ASME Amer Society of Mech Engrs ASSEM Assemble 裝配 ASSY Assembly 裝配 AUTH Authorized 授權的 AUTO Automatic 自動的 AUX Auxiliary 輔助的 AVG Average平均

AWG American Wire Gauge BC Bolt Circle 螺栓圓周 BET Between 之間 BEV Bevel 斜角

BHN Brinell Hardness Number 布氏硬度值 BLK Blank ,Block 空白 B/NM Bill of Material 材料費 BOT Bottom 底部 BP or B/P Blueprint 藍圖 BRG Bearing 軸承 BRK Break 破裂 BRKT Bracket 支架 BRO Broach 鉆孔 BRS Brass 黃銅 BRZ Bronze 青銅

B＆S Brown＆Shape 棕色＆形狀 BSC Basic 基本的 BUSH Bushing 套管

BWG Birmingham Wire Gauge CTO C Center-to-Center 中心到中心 CAD Computer Aided Design 電腦輔助設計 CAM Computer-Aided Mfg CAP Capacity 容量 CAP SCR Cap Screw 螺帽 CARB Carburize 使滲碳 CBORE Counterbore 擴孔 CCW Counter Clockwise 逆時針

CDRILL Counerdrill CDS Cold-Drawn Steel 看英文圖紙的一些資料

英文工程圖紙的右下邊是標題欄（相當于我們的標題欄和部分技術要求），其中有圖紙名稱（TILE）設計者（DRAWN）審查者（CHECKED）材料（MATERIAL）日期（DATE）比例（SCALE）熱處理（HEAT TREATMENT）和其它一些要求，如：

1)TOLERANCES UNLESS OTHERWISE SPECIFIAL 未注公差 2)DIMS IN mm UNLESS STATED 如不做特殊要求以毫米為單位 3)ANGULAR TOLERANCE±1° 角度公差±1° 4)DIMS TOLERANCE±0.1 未注尺寸公差±0.1 5)SURFACE FINISH 3.2 UNLESS STATED 未注粗糙度3.2 常見尺寸的標注及要求 2.1孔（HOLE）如：

（1）毛坯孔：3”DIA+1CORE 芯子 3“0+1;（2）加工孔：1”DIA1“;（3）锪孔：锪孔(注C＇BORE=COUNTER BORE锪底面孔);（4）鉸孔：1”/4 DIA REAM鉸孔1“/4;（5）螺紋孔的標注一般要表示出螺紋的直徑，每英寸牙數（螺矩）螺紋種類精度等級鉆深攻深，方向等如： 例1.6 HOLES EQUI-SPACED ON 5”DIA(6孔均布在5“圓周上（EQUI-SPACED=EQUALLY SPACED均布）DRILL 1”DIA THRO＇ 鉆1“通孔（THRO＇=THROUGH通）C/SINK22×6DEEP 沉孔22×6 例2.TAP 7”/8-14 UNF-3B THRO＇攻統一標準細牙螺紋，每英寸14牙，精度等級3B級

（注UNF=UNIFIED FINE THREAD美國標準細牙螺紋）1“DRILL 1”/4-20 UNC-3 THD7“/8 DEEP 4HOLES NOT BREAK THRO 鉆1”孔，攻1“/4美國粗牙螺紋，每英寸20牙，攻深7”/8,4孔不準鉆通（UNC=UCIFIED COARSE THREAD 美國標準粗牙螺紋）1“-14NS-2THRO 攻美國固定特種螺紋M1”,每英寸牙數14,精度等級為二級（注NS=NATIONAL SPECIAL THREAD:美國固定特種標準）

2.2倒角（CHAMFER）

例1/8×45°BEV 倒角1/8×45°（注BEV=BEVEI，斜面）1.5×45°CHAM 倒角1.5×45°(注CHAM=CHAMFER倒角)2.3方(SQUARE)例5“SQUARE5”×5“方 2.4剖視（SECTION）例SECTION A-AA-A剖面 2.5圓角半徑 例1”RR1“ RADIUS MUST BE SMOOTH AND BLEND INTO FACE 圓弧必須光滑且與平面相切 2.6加工余量 例DOTTED LINES INDICATED MAX FINISH 1”/8，虛線表示最大加工余量1“/8 2.7零件標記例

USE 5”/16 RAISED HAIRLINE LET-TERS MARKING ON ONE SIDE OF BODY用突起高為5"/16的細實線字母在本體一側打標記 關于鑄鍛件的技術要求

例1.FORGING MUST BE ANNEALED TO BE BELOW 203 BRINELL HARDNESS 鍛件必須退火處理，布氏硬度<203 例2.NORMALIZE TO 163-207BHNMUST BE FREE OF SCALE & RUST鍛件正火處理，布氏硬度163-207,鍛件表面不得有氧化皮和銹蝕

例3.FORGING TO BE SHOT OR SAND BLASTED鍛件需經噴丸或噴砂處理

例4.UNLESS OTHERWISE SPECIFIED DRAFT ANGLES 7°未注明鍛造拔模斜度7°

例5.CAST TO BE FREE OF EXCESSIVE FLASH 鑄件不得有過多的毛邊 例6.DRAFT ANGLE 2° UNLESS OTHER-WISE SPECIFIED 未注明鑄造拔模斜度2°

總之，看英文機械工程圖紙并不是高不可攀，只要堅持常看，熟記部分單詞即可。