研究生機(jī)械工程專業(yè)英語考試必背單詞

1、單詞lesson 1gear 齒輪, 傳動(dòng)裝置bearing 軸承cams 凸輪cams and followers 凸輪和從動(dòng)件couple 力偶mechanics 力學(xué)statics 靜力學(xué)，靜止?fàn)顟B(tài)dynamics動(dòng)力學(xué)，原動(dòng)力，動(dòng)力特性constraint forces 約束力applied forces 作用力electric , magnetic, and gravitational forces 電,磁,重力mating surface 嚙合表面,配合表面,接觸面meshing 嚙合，咬合，鉤住meshing teeth 嚙合齒journal bearing 滑動(dòng)軸承，向心滑動(dòng)軸

2、承metal-to-metal contact 金屬 - 金屬接觸overheating 過熱failure 失效flaking 薄片，表面剝落，壓碎spall 削，割，剝落，脫皮noise 噪音rough motion運(yùn)動(dòng)不精確inertia慣性particle 質(zhì)點(diǎn)rigid body剛體deformable可變形的，應(yīng)變的deformable body 變形體scalar 數(shù)量的，標(biāo)量的vectors矢量density密度mass質(zhì)量displacement位移velocity速度acceleration加速度moment力矩，彎矩momentum動(dòng)量，沖量lesson 2compres

3、sive壓縮的，有壓力的turning 車削rectilinear直線的micrometer 千分尺又稱螺旋測(cè)微器power hacksaws 弓鋸床shaper牛頭刨床thread 螺紋work：功muscular action肌肉動(dòng)作mechanical motion機(jī)械運(yùn)動(dòng)stretch an object拉伸對(duì)象tensile force：拉力in tension：受拉compressive force：壓力torsional force：扭力 torque：扭矩shearing force ：剪切力twist an object扭曲對(duì)象slide滑，脫落slip滑動(dòng)，滑移in com

4、pression受壓turning of a part對(duì)一個(gè)零件進(jìn)行車削加工wedging action:楔入作用chip ：切屑centers of the lathe車床的頂尖lathe dog車床夾頭centrifugal force ：離心力grinding wheel ：磨削砂輪bonding agent ：粘合劑abrasive particle：磨料顆粒centrifuge-type machines離心式機(jī)械centrifuge離心機(jī)，離心作用centrifugal force principles離心力原理centripetal force ：向心力rotary motion

5、:回轉(zhuǎn)運(yùn)動(dòng)rectilinear motion：直線運(yùn)動(dòng)hand tool手工工具power tool動(dòng)力工具feed：進(jìn)給shaping：采用牛頭刨床（shaper)進(jìn)行刨削加工power saw：弓鋸床，弓式鋸床the screw of a micrometer 意為“千分尺中的螺桿”harmonic and intermittent motion ：諧和運(yùn)動(dòng)和間歇運(yùn)動(dòng)simple harmonic motion ：簡(jiǎn)諧運(yùn)動(dòng)return stroke：快速回程shaper ram：刨床滑枕pulley滑輪screw螺絲釘belt帶link鏈lesson 3interactive互相作用的i

6、terative重復(fù)的, 反復(fù)的, 迭代的pinpoint 精確地定位或確認(rèn)equilibrium 平衡，均衡tractable 易于處理或操作的order of magnitude 數(shù)量級(jí)ideally理想的情況下so as to為了with any precision很少精確idealize理想化idealization 理想化strength of materials材料力學(xué)dynamics動(dòng)力學(xué)approximations近似值be inherent in為、所固有，是、的固有性質(zhì)render提出，給予，描繪degrading the result使結(jié)果降級(jí)pertinent有關(guān)pro

7、hibitive令人望而卻步influx流入，注入，涌進(jìn)，匯集lesson 5sprocket鏈輪snap ring 卡環(huán)universal joints萬向聯(lián)軸器self-aligning bearing 調(diào)心軸承，球面軸承, 自位軸承dry ice干冰shot-peening噴丸硬化處理pin銷key鍵spline花鍵couplings聯(lián)軸器nondriving wheel非驅(qū)動(dòng)輪idler gear空轉(zhuǎn)齒輪，換向齒輪be subjected to承受fluctuate變動(dòng)，波動(dòng)，起伏alternating bending stress交變彎曲應(yīng)力deflections撓度lateral

8、shaft deflection橫向軸的撓度angular deflection角偏轉(zhuǎn)non-self- aligning bearings非自調(diào)心軸承torsional deflection扭轉(zhuǎn)變形critical speed臨界速度attachment of the hub轂的附件keyway鍵槽axial軸向circumferential圓周方向positioning定位retaining固定retaining ring定位環(huán)hub-to-shaft attachments輪轂與軸之間的連接interference fit過盈配合hub bore轂孔bending moment彎矩col

9、d-rolling冷軋relative slope相對(duì)傾斜journal軸頸plain bearing 滑動(dòng)軸承l(wèi)esson 6clutch 離合器brake 制動(dòng)器friction 摩擦chain 鏈，鏈條timing belt 同步帶belt drive 帶傳動(dòng)coefficient of friction摩擦系數(shù)rayon人造纖維timing belt同步帶v-belt drive v帶傳動(dòng)foregoing在前的，前述的fatigue life疲勞壽命power transmitted電力傳輸rotatable shaft可以轉(zhuǎn)動(dòng)的軸，從動(dòng)軸rotating shaft轉(zhuǎn)動(dòng)軸，主動(dòng)軸i

10、nput shaft輸入軸output shaft輸出軸unloaded state空載狀態(tài)rotor轉(zhuǎn)子rotational inertia轉(zhuǎn)動(dòng)慣量torque capacity 扭矩容量kinetic and potential energy動(dòng)能和勢(shì)能provision 規(guī)定thermal capacity 熱容量thermal stress熱應(yīng)力thermal distortion熱變形rubbing velocity摩擦速度lining內(nèi)襯，襯套empirical value經(jīng)驗(yàn)值chain drives鏈傳動(dòng)gear drives齒輪傳動(dòng)speed ratio速比shaft sepa

11、ration distance軸間隔距離arbitrary center distance任意的中心距positive (no slip) drive強(qiáng)制(無滑動(dòng))傳動(dòng)synchronized motion同步運(yùn)動(dòng)conveyor systems, farm machinery, textile machinery傳送帶系統(tǒng)，農(nóng)用機(jī)械，紡織機(jī)械chain loop鏈環(huán)40-kw power ratings ：40千瓦的額定功率lesson 9ceramic bearing 陶瓷軸承silicon硅titanium 鈦adherence 粘附，附著gas turbine engines 燃?xì)鉁u輪

12、發(fā)動(dòng)機(jī)liquid lubricant液體潤滑劑exploit利用，發(fā)揮，使用tribological 摩擦學(xué)的ceramic rolling bearing陶瓷滾動(dòng)軸承thermo-mechanical熱機(jī)械tool steel工具鋼aeroengine航空發(fā)動(dòng)機(jī)practical temperature limit 實(shí)際的溫度上限virtual exclusion虛擬排斥hot pressed 熱壓hot isostatically pressed 熱等靜壓的silicon nitride si3n4rolling contact fatigue滾動(dòng)接觸疲勞low fracture tou

13、ghness低的斷裂韌性coefficient of thermal expansion熱膨脹系數(shù)thermal conductivity導(dǎo)熱系數(shù)thermal diffusivity熱擴(kuò)散系數(shù)，溫度擴(kuò)散率oxidation resistance抗氧化性hertzian contact stresses 赫茲接觸應(yīng)力solid lubricant固體潤滑劑synthetic lubricant合成潤滑劑unconventional lubricant非常規(guī)潤滑劑boundary lubrication邊界潤滑wear resistance耐磨性tribo-chemical film摩擦化學(xué)膜s

14、hear剪切，切斷heat stable熱穩(wěn)定imperative命令，絕對(duì)必要的，必不可少的lesson 14melting point熔點(diǎn)specific heat比熱specific gravity比重shrink fit 冷縮配合，收縮配合thermal conductivity熱導(dǎo)率，導(dǎo)熱率thermal expansion熱膨脹corrosion resistance耐蝕性reduce inertial force減小慣性力substitution 替換recrystallization temperature再結(jié)晶溫度annealing退火heat treating熱處理hot

15、working熱加工minor 微小的surface roughness 表面粗糙度metallurgical冶金學(xué)的titanium鈦thermal gradient熱梯度relative expansion相對(duì)膨脹glass-to-metal seals玻璃 - 金屬密封件shrink fit冷縮配合，收縮配合deterioration惡化，變質(zhì)，退化degradation降解，老化，退化petroleum 石油elevated temperature高溫alkalis堿oxygen, moisture, pollution, and acid rain氧氣，濕氣，污染和酸雨nonferr

16、ous metals, stainless steels, and nonmetallic materials, 有色金屬，不銹鋼，和非金屬材料cast iron鑄鐵chromium鉻protective film保護(hù)膜lesson 28basic size基本尺寸deviation偏差interchangeable互換性interchangeability互換性u(píng)nilateral, bilateral, and limit forms.單邊的，雙邊的和極限形式plus-or-minus加或減theoretical dimension理論尺寸basic dimension基本尺寸termin

17、ology術(shù)語definition 定義tolerance公差clearance fit間隙配合interference fit過盈配合transition fit過度配合selective assembly選擇裝配by trial and error用試湊法basic hole system基孔制basic shaft system基軸制international tolerance (it) grade公差等級(jí)tolerance symbols公差符號(hào)tolerance zone公差帶uppercase letter大寫字母lowercase letter小寫字母surface textu

18、re表面紋理surface finish表面光潔度roughness, waviness, lay and flaws.粗糙度，波紋度，加工紋理方向和缺陷irregularities in the surface表面不平度cutoff中止，截止superimpose重疊，疊加waviness波度interval間隔cracks, blow holes, checks, scratches裂紋，氣孔，檢查，劃痕lesson 43burr 毛刺saw 鋸hacksaw弓鋸plasma 等離子體sophistication復(fù)雜化，完善，采用先進(jìn)技術(shù)simplicity簡(jiǎn)單sophisticated復(fù)

19、雜的durable耐用的，耐久的alloy steel合金鋼carbide碳化物diamond金剛石harnessed駕馭，治理tough強(qiáng)硬deburr去毛刺，去飛翅welding焊接impose利用，施加影響nontraditional manufacturing processes非傳統(tǒng)制造工藝drilling鉆孔sawing鋸切broaching拉床electric motors電動(dòng)馬達(dá)hydraulics液壓gravity重力electric arcs電弧harness利用electrochemical 電化學(xué)plasmas等離子體jets of liquids and abrasi

20、ves液體和磨料射流magnetic field磁場(chǎng)explosive爆炸electric spark電火花high-frequency sound waves高頻聲波beams of electron電子束reject排斥，抵制in-process breakage過程中的破損aforementioned上述的，前面提到的reliability 可靠性vision systems, laser gages視覺系統(tǒng)，激光測(cè)量metallurgical冶金implementation履行l(wèi)esson 62conceive 構(gòu)思tedious 單調(diào)乏味的optimum 最佳效果informatio

21、n age信息時(shí)代metalworking金屬加工come full circle回到原地，繞了一圈interchangeability互換性specialized functions特殊功能integrated manufacturing system集成制造系統(tǒng)diversify多樣化reflex反射，映像，回復(fù)flexibility靈活性integration 集成superquality高質(zhì)量superproductivity高生產(chǎn)率conflicting不一致的，沖突的getting the most out如何充分利用quality assurance質(zhì)量保證materials h

22、andling材料處理schedule時(shí)間表，進(jìn)度表，計(jì)劃表shop floor車間distributed intelligence分布式智能microprocessors controlled machines微處理器控制的機(jī)器instantaneously瞬間，即時(shí)tighter 更緊producible可生產(chǎn)instantaneous瞬間work-in-process在制零件tedious乏味not to mention更何況lure吸引，誘惑contracted out.承包出去，訂合同把工作包出去lesson 64simulator 模擬裝置, 仿真裝置terrain 地區(qū), 地帶p

23、lanar 平面的marketable銷售closed-loop process閉環(huán)過程factory automation工廠自動(dòng)化central data base中央數(shù)據(jù)庫computer-aided designcomputer-aided manufacturing computer-aided product design計(jì)算機(jī)輔助產(chǎn)品設(shè)計(jì)computer-aided analysis計(jì)算機(jī)輔助分析 computer-aided drafting,計(jì)算機(jī)輔助繪圖design sensitivity analysis設(shè)計(jì)敏感性分析optimization最佳化，優(yōu)化model sim

24、ulator模型模擬器substitute替代laboratory or field test實(shí)驗(yàn)室或現(xiàn)場(chǎng)測(cè)試manufacturability生產(chǎn)能力on-line control在線控制simulate模擬prototype原型repetitive重復(fù)electrical and electronic circuits電氣和電子電路algorithm算法finite-element 有限元computational technique計(jì)算技術(shù)multi- body mechanical system多體機(jī)械系統(tǒng)formulating the equation制定公式numerical me

25、thod數(shù)值方法special-purpose program專用程序general- purpose program通用程序rigidly structure剛性結(jié)構(gòu)flexibility靈活性planar motion平面運(yùn)動(dòng)four-bar linkage四連桿機(jī)構(gòu)spatial motion空間運(yùn)動(dòng)rough terrain崎嶇的地形connectivity連通性，連接性force element力單元governing equation控制方程coordinate協(xié)調(diào)nonlinearity 非線性lesson 71industrial robot 工業(yè)機(jī)器人printed circ

26、uit boards印刷電路板shutdown停工，關(guān)閉 robot installation機(jī)器人安裝single- purpose machines單一用途的機(jī)器international organization for standardization (iso)國際標(biāo)準(zhǔn)化組織（iso）reprogrammable可重復(fù)編程multipurpose manipulator多功能機(jī)械手robot institute of america(ria)美國機(jī)器人協(xié)會(huì)（ria）japan industrial robot association(jira)日本工業(yè)機(jī)器人協(xié)會(huì)（jira）britis

27、h robot association (bra)英國機(jī)器人協(xié)會(huì)（bra）reprogrammable multifunctional manipulator可重新編程的多功能機(jī)械手multifunctional多功能multifunctional多功能end-effector末端執(zhí)行器articulated arm 關(guān)節(jié)臂articulated 關(guān)節(jié)式的，鉸鏈的u. s. atomic energy commission美國原子能委員會(huì)unsophisticated不復(fù)雜的materials handling machine材料搬運(yùn)機(jī)general motors corporation通用汽

28、車公司die casting machine壓鑄機(jī)die casting 壓力鑄造，壓鑄gripper手爪degrees of freedom (dof)自由度（dof）unimation萬能自動(dòng)化公司jointed-spherical robot關(guān)節(jié)式球面機(jī)器人welding, painting焊裝，涂裝inspection檢查fully automated production line全自動(dòng)生產(chǎn)線vehicle chassis汽車底盤conveyor輸送帶assemble組裝a sequence of一序列的 mass-produced printed circuit boards (p

29、cbs)大規(guī)模生產(chǎn)的印刷電路板（pcb）pick-and-place robot拾取和放置機(jī)器人surpassing 超越reliability可靠性inflation of wages通貨膨脹的工資imperative勢(shì)在必行，必要的parting分離的，離別的robot cells機(jī)器人單元danger zone危險(xiǎn)區(qū)marked off關(guān)閉標(biāo)記 precaution預(yù)防措施 shutdown system 停車系統(tǒng) setting位置，安裝，環(huán)境翻譯lesson2considerable attention is given to the action of centrifugal fo

30、rce in grinding wheels. that is, the bonding agent that holds the abrasive particles on the wheel must be stronger than the forces which tend to make the revolving wheel fly apart at high speeds. for this reason, the speed of a grinding wheel should not exceed the safe surface speed limit specified

31、by the manufacturer. centrifugal force increases with speed.對(duì)磨削用的砂輪來講離心力的影響要特別給以關(guān)注。即把磨料顆粒粘合在砂輪上的粘合劑它的粘合力必須大于使高速旋轉(zhuǎn)的砂輪分崩離析的離心力。因此，砂輪的轉(zhuǎn)速不能超過制造商給定的安全表面速度限制。離心力隨轉(zhuǎn)速的增加而增大。the principles of centrifugal force are used in the design of centrifuge-type machines. some centrifuges are used to separate chemicals

32、; others are used to remove impurities in metals by centrifugal casting processes. centrifugal force principles are also used in common appliances such as clothes dryers and in devices to control motor speeds and accelerate moving machines.離心力的這種原理用在離心型機(jī)器的設(shè)計(jì)中。一些離心分離機(jī)用于分離化學(xué)制品；還有的通過離心鑄造工藝分離金屬中的雜質(zhì)。離心力作

33、用也有普通的應(yīng)用如干衣機(jī)、控制發(fā)動(dòng)機(jī)轉(zhuǎn)速的裝置以及用于加速運(yùn)動(dòng)的機(jī)器。 centripetal force causes an object to travel in circular path. this action is caused by the continuous application of forces which tend to pull the object to the center. in other words, the inward force which resists the centrifugal force is called the centripetal

34、 force. the centripetal force of objects spinning at a constant rate produces an acceleration toward the center which is equal and opposite to the centrifugal force.向心力使物體沿著圓形軌道運(yùn)動(dòng)。這種現(xiàn)象的產(chǎn)生是由于將物體拉（軌道）中心的力的持續(xù)作用。換句話說，這種抵抗離心力的向內(nèi)的力就叫向心力。以固定速率作旋轉(zhuǎn)運(yùn)動(dòng)的物體的向心力產(chǎn)生一個(gè)向心的加速度，這個(gè)向心力與離心力大小相等，方向相反。 lesson3primarily, we

35、will be discussing things which are in “equilibrium,” i.e., not accelerating. however, if we look closely enough, everything is accelerating. we will consider many structural members to be “weightless”but they never are. we will deal with forces that act at a “point” but all forces act over an area.

36、 we will consider some parts to be “rigid”but all bodies will deform under load.首先，我們討論的是處于“平衡”狀態(tài)即沒有加速的物體。然而任何東西都在加速，如果我們觀察足夠仔細(xì)的話。我們認(rèn)為很多結(jié)構(gòu)件是“沒有重量”的但它們從來不是這樣；我們認(rèn)為力的作用在一個(gè)“點(diǎn)”上，但所有力都作用在一個(gè)區(qū)域上；我們認(rèn)為有些零件是“剛體的”但所有物體在負(fù)載下都會(huì)變形。we will make many assumptions that clearly are false. but these assumptions should al

37、ways render the problem easier, more tractable. you will discover that the goal is to make as many simplifying assumptions as possible without seriously degrading the result.我們都會(huì)作一些明顯是錯(cuò)誤的假設(shè)。但這些假設(shè)常可能使問題簡(jiǎn)化，更容易駕馭。你會(huì)發(fā)現(xiàn)目標(biāo)是只要不使結(jié)果嚴(yán)重降級(jí)（歪曲），就盡可能多的做出簡(jiǎn)化的假設(shè)。generally there is no clear method to determine how co

38、mpletely, or how precisely, to treat a problem: if our analysis is too simple, we may not get a pertinent answer; if our analysis is too detailed, we may not be able to obtain any answer. it is usually preferable to start with a relatively simple analysis and then add more detail as required to obta

39、in a practical solution. 通常沒有明確的方法去確定怎么完整（全面）或精確的去處理問題：如果我們的分析太簡(jiǎn)單，（我們）可能不會(huì)得到一個(gè)中肯的答案；如果我們的分析太詳細(xì)，（我們）也許得不到任何答案。通常更好的是從相對(duì)簡(jiǎn)單的分析開始，添加一些需要的細(xì)節(jié)以獲得實(shí)用解。 during the past two decades, there has been a tremendous growth in the availability of computerized methods for solving problems that previously were beyond

40、solution because the time required to solve them would have been prohibitive. at the same time the cost of computer capability and use has decreased by orders of magnitude. 5 we are experiencing an influx of personal computers on campus, in the home, and in business.在過去20年間，用以解決問題的計(jì)算機(jī)方法可用性得到了巨大的提升，過

41、去不能解決是因?yàn)榻鉀Q問題所需要的時(shí)間受到限制。同時(shí)計(jì)算機(jī)的性能成本和使用成本有成數(shù)量級(jí)的降低。我們?cè)谛@里、在家中，在商務(wù)場(chǎng)所都正在經(jīng)歷著一個(gè)“個(gè)人計(jì)算機(jī)”的浪潮。lesson51.keep shafts as short as possible, with bearings close to the applied loads. this reduces deflections and bending moments, and increase critical speeds.2. place necessary stress raisers away from highly stresse

42、d shaft regions if possible.9 consider local surface strengthening processes (as shot-peening or cold-rolling).10 3.use inexpensive steels for deflection-critical shafts, as all steels have essentially the same modulus.4.when weight is critical , consider hollow shafts.1.保持軸盡可能短，與軸承接近施加的載荷。這減少了變形和彎曲

43、力矩，并增大臨界速度。2.盡可能使必要的應(yīng)力集中源遠(yuǎn)離軸上承受較高應(yīng)力的區(qū)域?？紤]采用局部表面強(qiáng)化工藝（諸如噴丸強(qiáng)化和常溫滾壓）3.使用廉價(jià)的鋼材用于偏轉(zhuǎn)臨界軸，因?yàn)樗械匿摼哂谢鞠嗤膹椥阅Ａ俊?，當(dāng)重量是至關(guān)重要時(shí)，考慮空心軸。lesson9the importance of requiring a lubricating film cannot be over emphasized, even when using ceramic materials.7 unlubricated silicon nitride or silicon carbide do not inherently

44、have low friction, nor good wear resistance. these properties can be obtained with the aid of solid lubricants which are compatible with the materials.silicon nitride, lubricated for example with graphite containing high temperature additive, can form a tribo-chemical film which reduces the coeffici

45、ent of friction and, as a consequence, minimizes heat generation. the reduction in friction depends on the easier shearing of the film compared with the base material.for bearing operation at ultra-high temperaturesabove 550solid lubricants which are more heat stable than graphite are being consider

46、ed. it is imperative that the development of a complex tribological system such as a high temperature solid lubricated, ceramic bearing is conducted with full understanding of the individual tribological relationship of the various components.潤滑膜的重要性怎么強(qiáng)調(diào)都不過分，即使采用陶瓷材料時(shí)也是這樣。無潤滑的氮化硅或碳化硅不固有低的摩擦，也沒有良好的耐磨

47、性。這些性質(zhì)可在固體潤滑劑的幫助獲得，這些性質(zhì)與材料相兼容。以氮化硅的潤滑為例，用含有高溫添加劑的石墨，可形成摩擦化學(xué)膜從而降低摩擦系數(shù)，結(jié)果，減少熱量的產(chǎn)生。摩擦的減少取決于膜與基材相比誰更容易被切落。對(duì)于工作在超高溫（高于550）下的軸承來說比石墨有更好的熱穩(wěn)定性的固體潤滑劑正在被考慮。一個(gè)復(fù)雜的摩擦系統(tǒng)的發(fā)展是很有必要的，如高溫固體潤滑劑。陶瓷軸承被引入以充分理解各組成部件間的單獨(dú)摩擦關(guān)系。lesson14resistance to corrosion depends on the composition of the material and on the particular env

48、ironment. corrosive media may be chemicals (acids, alkalislklis , and salts), the environment (oxygen, moisture, pollution, and acid rain), and water (fresh or salt water).5 nonferrous metals, stainless steels, and nonmetallic materials, generally have high corrosion resistance. steels and cast iron

49、s usually have poor resistance and must be protected by various coatings and surface treatments.抗腐蝕性取決于材料的成分和特定的環(huán)境。腐蝕媒介可以是化學(xué)品（酸、堿和鹽），環(huán)境（氧、潮濕、污染和酸雨）和水（清水或鹽水）。有色金屬、不銹鋼和非金屬材料通常有高抗腐蝕性。鋼和鑄鐵通?？垢g性差，必須有各種涂層和表面處理保護(hù)。the usefulness of some level of oxidation ksidein is exhibited in the corrosion resistance of

50、 aluminum, titanium, and stainless steel. aluminum develops a thin (a few atomic layers), strong, and adherent hard-oxide film (al2o3) that better protects the surface from further environmental corrosion.titanium develops a film of titanium taiteinjm oxide (tio2). a similar phenomenon occurs in sta

51、inless steels, which (because of the chromium present in the alloy) develop a protective film on their surfaces. when the protective film is scratched and exposes the metal underneath, a new oxide film begins to form.某些等級(jí)的氧化物的有用性表現(xiàn)在鋁、鈦和不銹鋼的抗腐蝕性上。鋁產(chǎn)生一層薄的（一些原子層）、牢固的附著氧化膜（al2o3）以保護(hù)表面不進(jìn)一步的腐蝕。鈦產(chǎn)生一層氧化鈦(ti

52、o2）膜。不銹鋼也有相似的現(xiàn)象，（因?yàn)楹辖鹬杏欣樱┍砻娈a(chǎn)生一層保護(hù)膜，當(dāng)保護(hù)膜擦損并露出金屬里層時(shí)，一層新的氧化膜又開始形成了。lesson28roughness: the finest of the irregularities in the surface caused by the manufacturing process used to smooth the surface. roughness height is measured in micrometers (m ) or microinches (in ).waviness: a widely spaced variation

53、 that exceeds the roughness width cutoff measured in inches or millimeters; roughness may be regarded as a surface variation superimposed on a wavy surface. lay: the direction of the surface pattern caused by the production method used.flaws: defects occurring infrequently or at widely varying inter

54、vals on a surface, including cracks, blow holes, checks, scratches, and the like; the effect of flaws is usually omitted in roughness height measurements.粗糙度：由用來使工件表面光滑的加工工藝所造成的最細(xì)微的表面不平度。表面粗糙度的高度采用微米或微英寸作為測(cè)量的單位。波度：是超過粗糙度界限的大間隔偏差，采用英寸或毫米測(cè)量。可將粗糙度看做疊加在波度表面上的表面不平度。加工紋理方向：由所采用的加工方法所產(chǎn)生的表面刀痕圖案的方向。缺陷：不經(jīng)常出現(xiàn)或

55、者在很大區(qū)間內(nèi)才會(huì)出現(xiàn)的表面瑕疵，包括裂紋、氣孔、微細(xì)裂紋、劃痕等。缺陷的影響通常在粗糙度的高度測(cè)量中被忽略。lesson 62 people are enabled to do their jobs better. by eliminating tedious calculations and paperwork- not to mention time wasted searching for information-the computer not only allows workers to be more productive but also frees them to do wh

56、at only human beings can do: think creatively.computer integration may also lure new people into manufacturing. people are attracted because they want to work in a modern, technologically sophisticated environment.in manufacturing engineering, cad/cam decreases tool design, nc-programming, and planning times while speeding the response rate, which will eventually permit in-house staff to perform work that is currently being contracted out.可使人們更好地完成工作。通過避免冗長的計(jì)算和書寫工作這還不算查找資料所浪費(fèi)的時(shí)間計(jì)算機(jī)不僅可以使人們更有效的工作，而且還能把他們解放出來去做只有人類才能做的工作：創(chuàng)造性的思考