機(jī)械工程專業(yè)英語課本翻譯

1、機(jī)械專業(yè)外語1（設(shè)計(jì)）楊化動(dòng)華北電力大學(xué)機(jī)械工程系設(shè)計(jì)教研室緒論1.專業(yè)英語Special EnglishProfessional English2.基礎(chǔ)英語Elementary English3.教學(xué)要求主要培養(yǎng)學(xué)生專業(yè)文獻(xiàn)的閱讀和翻譯水平，掌握一定的專業(yè)詞匯和專業(yè)術(shù)語，拓寬專業(yè)知識面，了解機(jī)械專業(yè)前沿的相關(guān)內(nèi)容。教學(xué)內(nèi)容1.教材機(jī)械工程專業(yè)英語中國電力出版社出版2.教學(xué)章節(jié)PART Mechanical Materials and Heat Treatment 1. Ferrous Metals and Their Use2. Nonferrous Metals4. Castings5.

2、Forging7. Heat Treatment8. Engineering Material （續(xù)前頁）教學(xué)章節(jié)PART II Mechanical Elements and Mechanisms1. Transmission2. Gear3. Belt Drive4. Coupling5. Bearing9. Properties of Hydraulic Fluids PART Mechanical Design 1. Mechanical Design 學(xué)習(xí)本課程注意事項(xiàng)1.尊重原文專業(yè)文獻(xiàn)較為嚴(yán)謹(jǐn)，因此翻譯過程中不需要加入過多的修飾詞語，不要主觀隨意添加2.避免“專業(yè)笑話”Drill

3、ing a holeMachine toolsLesson 1 Ferrous metals and Their Use Words and ExpressionsParagraph AnalysisParagraph 1It is known that ferrous metals are very important in the world, and have the greatest importance for industry. 眾所周知黑色金屬是非常重要的，對工業(yè)來說最為重要。 More than 90% by weight of the metallic materials u

4、sed by human beings are ferrous alloys. 人類使用的90%以上的金屬材料為黑色金屬合金Metals consisting of iron combined with some other elements are known as ferrous metals; all the other metals are called nonferrous metals. 由鐵和一些其他元素構(gòu)成的金屬被稱為黑色金屬；所有其他的金屬被稱為有色金屬。Ferrous metals include plain-carbon steels, alloy and tool st

5、eels, stainless steels, and cast irons. 黑色金屬包括普通碳鋼、合金鋼、工具鋼、不銹鋼和鑄鐵。 plain-carbon steels普通碳鋼, alloy and tool steels,合金鋼、工具鋼、 stainless steels,不銹鋼and cast irons鑄鐵These groups of ferrous alloys have a wide variety of characteristics and applications. 這些黑色金屬合金具有各種特性且應(yīng)用廣泛Paragraph 2Carbon steels are the m

6、ost common steels used in industry. 碳鋼是工業(yè)中最常使用的一種鋼材。These eminently practical materials find applications from ball bearings to metal sheet formed into automobile bodies. 這些實(shí)用材料被應(yīng)用于從滾珠軸承到汽車殼體的金屬板。 The properties of these steels depend only on the percentage of carbon they contain. 這些鋼的性質(zhì)僅僅依賴于碳的含量。Lo

7、w carbon steel containing from 0.02 to 0.25 percent carbon, and they are very soft and can be used for bolts and for machine parts that do not need strength. 低碳鋼含碳量0.02-0.25%，它們很軟，能夠用于螺栓和不需要強(qiáng)度的機(jī)械零件。Medium carbon steel containing from 0.25 to 0.6 percent carbon which is a better grade and stronger th

8、an low carbon steel. 中碳鋼含碳量0.25-0.6%，相比低碳鋼品質(zhì)更好，強(qiáng)度更高。 High carbon steel containing from 0.6 to 2.11 percent carbon, these steel is sometimes called “ tool steel ”. 高碳鋼含碳量0.6-2.11%，這些鋼有時(shí)被稱為工具鋼。They obtain high hardness by a quench and temper heat treatment. 它們通過淬火和回火熱處理獲得高硬度。Their applications include

9、 cutting tools in machining operations, dies for die casting, forming dies, and other in which a combination of high strength hardness, toughness, or temperature resistance is needed. 它們的應(yīng)用包括機(jī)加工中的切削刀具、壓鑄中的模具、成型模以及其他，在其中，和具有高強(qiáng)度、硬度、剛性或耐熱性的元素的結(jié)合是必須的。淬火 鋼的淬火是將鋼加熱到臨界溫度Ac3（亞共析鋼）或Ac1（過共析鋼）以上某一溫度，保溫一段時(shí)間，使之全

10、部或部分奧氏體1化，然后以大于臨界冷卻速度的冷速快冷到Ms以下（或Ms附近等溫）進(jìn)行馬氏體（或貝氏體）轉(zhuǎn)變的熱處理工藝。 淬火的目的是使過冷奧氏體進(jìn)行馬氏體或貝氏體轉(zhuǎn)變，得到馬氏體或貝氏體組織，然后配合以不同溫度的回火，以大幅提高鋼的強(qiáng)度、硬度、耐磨性、疲勞強(qiáng)度以及韌性等，從而滿足各種機(jī)械零件和工具的不同使用要求。也可以通過淬火滿足某些特種鋼材的的鐵磁性、耐蝕性等特殊的物理、化學(xué)性能。淬火能使鋼強(qiáng)化的根本原因是相變，即奧氏體組織通過相變而成為馬氏體組織（或貝氏體組織）。回火回火是工件淬硬后加熱到AC1以下的某一溫度，保溫一定時(shí)間，然后冷卻到室溫的熱處理工藝?；鼗鹨话憔o接著淬火進(jìn)行，其目的是：(

11、a)消除工件淬火時(shí)產(chǎn)生的殘留應(yīng)力，防止變形和開裂；(b)調(diào)整工件的硬度、強(qiáng)度、塑性和韌性，達(dá)到使用性能要求；(c)穩(wěn)定組織與尺寸，保證精度；(d)改善和提高加工性能。因此，回火是工件獲得所需性能的最后一道重要工序。 按回火溫度范圍，回火可分為低溫回火、中溫回火和高溫回火。Paragraph 3Stainless steel require alloy additions to prevent damage from a corrosive atmosphere. 不銹鋼需要添加合金防止腐蝕環(huán)境的破壞。Stainless steels are more resistant to rusting

12、and staining than carbon and low alloy steels, due primarily to the presence of chromium addition. 不銹鋼由于加入了鉻元素，其抗銹蝕和污斑能力高于碳鋼和低合金鋼。The amount of chromium is at least 12.7 percent and usually as high as 30 percent, which permits a thin protective surface layer of chromium oxide to form when steel is e

13、xposed oxygen. 鉻的含量至少12.7%，通常達(dá)到30%，當(dāng)鋼暴露于氧氣環(huán)境中時(shí)，它允許形成一層薄的鉻氧化保護(hù)層。There are four categories of stainless based on crystal structure and strengthing mechanism. They are the ferritic stainless steel, martensitic stainless steel, austenitic stainless steels and precipitation hardening stainless steels. 根據(jù)

14、不銹鋼的組織和力學(xué)性能來分，不銹鋼可以分為四種：鐵素體不銹鋼，奧氏體不銹鋼，馬氏體不銹鋼和沉淀硬化不銹鋼。Paragraph 4The austenitic stainless steels have the austenite structure retained at room temperature.奧氏體不銹鋼在室溫保留奧氏體結(jié)構(gòu)。The austenite has the fcc structure and is stable above 910. 奧氏體有面心立方結(jié)構(gòu)， 910以上處于穩(wěn)定狀態(tài)。This structure can occur at room temperature

15、 when it is stabilized by an appropriate alloy addition such as nickel. 通過添加諸如鎳等恰當(dāng)?shù)暮辖?，這一結(jié)構(gòu)能夠在室溫下形成。面心立方晶格面心立方晶格（胞）（F.C.C.晶格）面心立方晶胞如圖所示，金屬原子分布在立方體的八個(gè)角上和六個(gè)面的中心。面中心的原子與該面四個(gè)角上的原子緊靠。具有這種晶格的金屬有鋁（Al）、銅（Cu）、鎳（Ni）、金（Au）、銀（Ag）、-鐵（-Fe，9121394）等。面心立方晶胞的特征是：一、晶格常數(shù)：a=b=c,=90二、晶胞原子數(shù)：1/88+1/26=4（個(gè)）三、原子半徑：原子=四分之根號三a

16、四、致密度：（74%） 體心立方晶格體心立方晶格的晶胞中，八個(gè)原子處于立方體的角上，一個(gè)原子處于立方體的中心，角上八個(gè)原子與中心原子緊靠。具有體心立方晶格的金屬有鉀（K）、鈦（Ti）、鉬（Mo)、鎢（W）、釩（V）、-鐵（-Fe，912）等。 單位晶胞原子數(shù)為2配位數(shù)為8原子半徑根號（3）/4 a(設(shè)晶格常數(shù)為a)致密度0.68 體心立方晶格（胞）（晶格）單位晶胞原子數(shù)為2 Without the high nickel content, the bcc structure is stable, as seen in the ferritic stainless steels. 如果沒有高的鎳

17、含量，體心立方結(jié)構(gòu)是穩(wěn)定的，如鐵素體不銹鋼。 For many applications not requiring the high corrosion resistance of austenitic stainless steels, these lower alloy (and less expensive) ferritic stainless steels are quite serviceable. 對于許多不需要高腐蝕抵抗能力的奧氏體不銹鋼應(yīng)用來說，這些低合金鐵素體不銹鋼可用。A rapid quench heat treatment discussed later allow

18、s the formation of a more complex body centered tetragonal crystal called martensite. 后面討論的快速淬火熱處理允許以立方晶體為中心的更復(fù)雜基體的形成，稱為馬氏體。tetragonal: 四角形的This crystal structure yields high strength and low ductility. 這種晶格結(jié)構(gòu)具有高強(qiáng)度、低延展性。As a result, these martensitic stainless steels are excellent for applications s

19、uch as cutlery and springs. 結(jié)果，這些馬氏體不銹鋼對于諸如刀具和彈簧等應(yīng)用來說是非常優(yōu)秀的。Precipitation hardening is another heat treatment. Essentially, it involves producing a multiphase microstructure from a single phase one. 沉淀硬化是另外一種熱處理。本質(zhì)上說，它涉及到從一個(gè)單一相產(chǎn)生多相微結(jié)構(gòu)。The result is increased resistance to dislocation motion and, the

20、reby, greater strength or hardness. 結(jié)果是位錯(cuò)運(yùn)動(dòng)阻力增加，因此強(qiáng)度和硬度變得更高。 Precipitation hardening stainless steels can be found in applications such as corrosion resistant structural members. 沉淀硬化不銹鋼能夠在諸如抗腐蝕結(jié)構(gòu)件應(yīng)用中發(fā)現(xiàn)。Paragraph 5Cast iron are iron-carbon alloys that pass through the eutectic reaction during solidi

21、fication and greater than 2.11 percent carbon. 鑄鐵是鐵和碳的合金，碳含量大于2.11%，通過在結(jié)晶過程中的共晶反應(yīng)得到。 There are five important types of cast irons. 有五種重要類型的鑄鐵。White cast iron contains massive amounts of cementite and is a hard, brittle, unmachinable alloy. 白鑄鐵包含大量的滲碳體，是硬、脆和不能加工的合金。Gray cast iron contains small, inte

22、rconnected graphite flakes that cause low strength and ductility. 灰鑄鐵含有小的、互相連接的片狀石墨，造成低強(qiáng)度和低塑性。A significant silicon content (2 to 3 percent) promotes graphite precipitation rather than cementite. 重要的硅含量促進(jìn)石墨而不是滲碳體沉淀。The sharp, pointed graphite flakes contribute to characteristic brittleness in gray i

23、ron. 鋒利的點(diǎn)狀的石墨片使灰鑄鐵很脆。Malleable cast iron is produced by the heat treatment of white iron,causing cementites decomposed to irregular but rounded clumps of graphite. 可鍛鑄鐵通過白鑄鐵熱處理產(chǎn)生，導(dǎo)致滲碳體分解為不規(guī)則的圓形石墨塊。This graphite form permits good strength, ductility and toughness in the iron. 這種石墨形式允許良好的強(qiáng)度、塑性和剛度。Duct

24、ile or nodular cast iron contains spheroidal graphite particles. 球墨鑄鐵包含球狀的石墨顆粒。These spheroidal graphite are obtained during solidification by the addition of small amounts of magnesium to the molten iron. 球墨鑄鐵指通過在結(jié)晶過程中添加一些鎂元素作為球化劑而得到的。This resulting ductile iron derives its name from the improved m

25、echanical properties compacted graphite cast iron contains vermicular graphites. 這種球墨鑄鐵因?yàn)樘岣吡W(xué)性能而獲得他的名字，蠕墨鑄鐵含有蠕蟲狀石墨。They are also obtained during solidification by the addition of magnesium or rare earth elements. 它們也通過加入鎂或稀土元素凝固而獲得。The structure and properties of compacted cast iron are intermediate

26、 between gray and ductile irons. 蠕墨鑄鐵的性質(zhì)和結(jié)構(gòu)介于灰鑄鐵和球墨鑄鐵之間。Lesson 2 Nonferrous metals Words and ExpressionsParagraph 1Although ferrous alloys are used in the majority of metallic applications in current engineering designs, but nonferrous alloys play a large and indispensable role in our technology. 盡管

27、黑色金屬合金用于目前大多數(shù)工程設(shè)計(jì)的金屬材料應(yīng)用，但是有色合金在我們的科技中也起到了非常巨大和必需的角色。The most important nonferrous metals are copper, aluminum, lead, zinc, tin, but all these metals are used much less than ferrous metals, because the ferrous metals are much cheaper. 最重要的有色金屬是銅、鋁、鉛、鋅、錫，但是這些金屬的應(yīng)用遠(yuǎn)低于黑色金屬，因?yàn)楹谏饘俑阋?。Paragraph 2Aluminum

28、 are best known for low density and corrosion resistance. 鋁眾所周知密度低，耐腐蝕能力強(qiáng)。3 or one third the density of steel. 密度為，鋼密度的1/3。Although aluminum alloys have relatively low tensile properties compared to steel, their strength-to-weight ratio is excellent. 盡管鋁合金相對鋼來說具有更低的拉伸性質(zhì)，但是它們具有優(yōu)良的強(qiáng)度重量比。Aluminum is of

29、ten used when weight is an important factor, as in aircraft and automotive applications. 當(dāng)重量是一個(gè)重要因素的時(shí)候，鋁經(jīng)常被使用，比如飛機(jī)和汽車。On the other hand, aluminum often does not play an endurance limit in fatigue, so failure eventually occurs even at rather low stress. 另外，鋁疲勞極限較低，因此即使在低應(yīng)力下也會(huì)失效。Because of its low mel

30、ting point, aluminum does not perform well in the high temperatures. 因?yàn)榈腿埸c(diǎn)，鋁不能很好的應(yīng)用于高溫環(huán)境下。Finally, aluminum alloys have a low hardness, leading to poor wear resistance. 最后，鋁合金硬度低，耐磨損能力低。Aluminum alloys can be subdivided into two groups, wrought aluminum and casting aluminum alloys. 鋁合金可以劃分為兩類：形變鋁合金和

31、鑄造鋁合金Wrought alloys are shaped by plastic deformation. 形變鋁合金通過塑性變形而形狀改變。They have compositions and microstructures significantly different from casting alloys. 它們具有不同于鑄造合金的成分和微結(jié)構(gòu)。It reflects the different requirements of manufacturing process. 它反映了制造過程的不同要求。Within wrought alloys group we can divide

32、the alloys into two subgroups- heat treatable and nonheat treatable alloys. 在形變合金中，我們能夠把合金劃分成兩類：可熱處理合金和不可熱處理合金。Heat treatable alloys have a high hardness,whereas nonheat treatable alloys are hardend by solid solution strengthing. 熱處理合金具有高硬度，然而不可熱處理合金通過固溶時(shí)效強(qiáng)化硬化。如圖所示，合金在平衡狀態(tài)圖上有固溶度的變化，并且固溶度隨溫度降低而減小，如果將

33、C0成分的合金自單相固溶體狀態(tài)緩慢冷卻到固溶度線(MN)以下溫度(如T3)保溫時(shí)，相將從相固溶體中脫溶析出，相的成分將沿固溶度線變化為平衡濃度Cl，這種轉(zhuǎn)變可表示為(C0)(C1)+，反應(yīng)產(chǎn)物為呈平衡狀態(tài)的(+)雙相組織。將這種雙相組織加熱到固溶度線以上某一溫度(如T1)保溫足夠時(shí)間，將獲得均勻的單相固溶體相，然后速冷，抑制相分解，獲得在室溫下過飽和的相固溶體，這種處理稱為固溶處理。由于這種處理與前述的淬火處理相似，故有時(shí)也稱為淬火，但與淬火有本質(zhì)的區(qū)別。固溶處理獲得的過飽和固溶體在室溫或較高溫度下等溫保持時(shí)，溶質(zhì)原子會(huì)在固溶體晶格中的一定區(qū)域內(nèi)聚集或組成第二相，這種現(xiàn)象稱為析出。在析出過程中

34、，合金的力學(xué)性能、物理性能和化學(xué)性能等隨之發(fā)生變化，這種現(xiàn)象稱為時(shí)效。室溫下產(chǎn)生的時(shí)效稱為自然時(shí)效，高于室溫的時(shí)效稱為人工時(shí)效。由于第二相的析出，使合金的強(qiáng)度和硬度升高的現(xiàn)象稱為時(shí)效強(qiáng)化，是強(qiáng)化合金材料的重要途徑之一。能夠發(fā)生時(shí)效現(xiàn)象的合金稱為時(shí)效合金，成為這種合金的條件是能夠形成有限固溶體且其固溶度隨溫度的降低而減小。固溶時(shí)效強(qiáng)化處理主要用于沉淀硬化不銹鋼及非鐵合金如Al-Cu-Mg系合金、復(fù)雜青銅中。高錳鋼或高鉻高鎳鋼這類奧氏體鋼常用固溶處理來抑止緩冷過程中碳化物的析出以保證鋼的耐磨性或耐蝕性，方法是將鋼加熱到10501100保溫后在水中冷卻。Paragraph 3Copper alloy

35、s possess a number of superior properties. 銅合金擁有許多優(yōu)良的性質(zhì)。Their excellent electrical conductivity makes copper alloys the leading material for electrical wiring. 它們優(yōu)良的導(dǎo)電能力使得銅合金是電線中的重要材料。Their excellent thermal conductivity leads to applications for radiators and heat exchangers. 它們優(yōu)良的導(dǎo)熱性可以用于散熱器和熱交換器。S

36、uperior corrosion resistance is exhibited in marine and other corrosive environments. 優(yōu)良的耐腐蝕能力體現(xiàn)在海洋或其他腐蝕環(huán)境中。The fcc structure contributes to their generally high ductility and formability. 面心立方結(jié)構(gòu)使它具有較高的延展性和成型能力。Copper alloys are also unique in that they may be selected to produce an appropriate decr

37、oative color. 銅合金也是獨(dú)一無二的，就在于它們可以被選擇來作為裝飾性的顏色。Pure copper is red. 純銅是紅色的。However zinc additions produce yellow color and nickel produce a silver color. 然而加入鋅之后產(chǎn)生黃色，加入鎳之后產(chǎn)生銀色。The copper can take advantage of all of the strengthening mechanism. 銅能夠利用所有的強(qiáng)化機(jī)理。So there are a myriad of copper-base alloys.

38、因此有許多銅基合金。The copper-zinc alloys are known as brass. 銅鋅合金為黃銅Manganese bronze is a particularly high-strength alloy containing manganese as well as zinc for solid solution strengthening.錳青銅尤其是高強(qiáng)度的合金，含有錳和鋅用于固溶時(shí)效強(qiáng)化 A copper-nickel-zinc ternary alloy is called nickel silver. 銅-鎳-鋅三元合金被稱為鎳黃銅。Although it

39、does have a silver color, but it really has no silver present. 盡管它有銀色，但是它不含有銀。The formability of these alloys approaches that of copper-zinc alloys. 這些合金的成型能力接近銅鋅合金。Magnesium alloys have even lower density than aluminum and, as a result, appear in numerous structural applications such as aerospace d

40、esigns, high speed machinery, and transportation and materials handling equipment. 鎂合金密度更低，常常用于諸如航天設(shè)計(jì)、高速機(jī)械、運(yùn)輸設(shè)備和材料熱處理設(shè)備等無數(shù)結(jié)構(gòu)應(yīng)用。However, magnesium has a low modulus of elasticity and poor resistance to fatigue,wear.然而，鎂合金具有比較低的彈性模量，并且抗疲勞和耐磨損性能也比較差。Magnesium also pose a hazard during casting and machi

41、ning, since it combines easily with oxygen and burns. 鎂在鑄造和加工過程中存在危害，由于它容易和氧氣結(jié)合并且燃燒。Finally, the response of magnesium to strengthening mechanisms is relatively poor. 最終，鎂對強(qiáng)化機(jī)理的響應(yīng)是相對較差的。In magnesium alloys, strengthening is achieved by solid solution strengthening, strain strengthening; grain size c

42、ontrol, dispersion strengthening, and age harding. 所以，鎂合金是通過固溶強(qiáng)化，應(yīng)變強(qiáng)化，細(xì)晶強(qiáng)化，彌散強(qiáng)化和時(shí)效強(qiáng)化來提高其力學(xué)性能。 As in aluminum alloys, the solubility of the alloying elements in magnesium is rather low, so the degree of solid solution strengthening is limited. 在鋁合金中，合金元素在鎂中的溶解性很低，因此固溶時(shí)效強(qiáng)化程度有限。Paragraph 4Nickle alloys

43、 are used for corrosion protection and for high temperature resistance. 鎳合金被用于腐蝕保護(hù)和耐高溫環(huán)境中。It takes advantages of its high melting points and high strengths. 它充分利用它的高熔點(diǎn)和高強(qiáng)度。The lattice of nickle is FCC structures and has good formability. 鎳晶格是面心立方結(jié)構(gòu)，有良好的成型能力。Nickle alloys have much in common with coo

44、per alloys. 鎳合金在很多方面和銅合金相同。We have already used the Ni-Cu system as the classic example of complete solid solubility. 我們已經(jīng)使用鎳-銅系統(tǒng)作為完整固溶的經(jīng)典例子。When copper is added to nickle, the maximum strength is obtained near 60 percent Ni. 當(dāng)銅添加到鎳中，最大強(qiáng)度達(dá)到鎳的60%。A number of alloys, called Monels, contain approximate

45、ly this composition. 許多合金稱為蒙乃爾銅-鎳合金 ，大約包含這一成分。They are used in salt water and at a relative high temperature for their strength and corrosion resistance. 它們被用在鹽水中和相對高溫環(huán)境中，因?yàn)樗鼈兊膹?qiáng)度和耐蝕能力。 Nickles is harder than copper, but monel is harder than nickle. 鎳比銅硬度更高，但是蒙乃爾比鎳硬度更高。Nickle exhibits excellent corro

46、sion resistance and high temperature strength. 鎳具有良好的耐蝕能力和高溫強(qiáng)度。Some of the monels contain small amounts of aluminum and titanium. 一些蒙乃爾中包含小量的鋁和鈦。These alloys show an age-hardening. 這些合金時(shí)效強(qiáng)化。Superalloys contain large amounts of alloying elements.超合金包含大量的合金元素 These elements can produce a combination o

47、f high strength at elevated temperature, resistance to deformationg at temperatures up to 1000, and resistance to corrosion.這些元素能夠在升高的溫度中具有高強(qiáng)度，溫度達(dá)到 1000具有較好的抗變形能力和耐蝕性。There are three categories of superalloys. 有三種超合金They are nickle base alloy, iron-nickle base alloy, and cobalt base alloy. 他們分別是：以鎳為

48、基的合金，以鐵-鎳為基的合金，以鈷為基的合金。 Typical use includes vanes for turbine and jet engines, heat exchangers, chemical reaction vessel components, and heat-treating equipment. 典型的應(yīng)用包括渦輪和噴氣式發(fā)動(dòng)機(jī)的葉片、熱交換器、化學(xué)反應(yīng)容器和熱處理設(shè)備。Paragraph 5Different metals are produced in different ways, but almost all the metals are found in

49、the form of metal ore(iron ore, copper ore, etc.). 不同的金屬制造方法也不一樣，但是大多金屬都是通過各種各樣金屬礦石提煉出來的（例如：鐵礦石，銅礦石等）。 The ore is a mineral consisting of a metal combined with some impurities. 礦石由金屬和一些雜質(zhì)組成。In order to produce a metal from some metal ore, we must separate these impurities from the metal, that is don

50、e by metallurgy. 為了從金屬礦石中提煉金屬，我們必須把這些雜質(zhì)和金屬分離，通過冶金實(shí)現(xiàn)。Lesson 3. Ceramics and Other Materials Paragraph 1A ceramic is an inorganic, non-metallic solid prepared by the action of heat and subsequent cooling. 陶瓷是一個(gè)無機(jī)非金屬固體，通過熱行為和接下來的冷卻實(shí)現(xiàn)。Ceramic materials may have a crystalline or partly crystalline struct

51、ure, or may be amorphous (e.g., a glass). 陶瓷材料可能是結(jié)晶、部分結(jié)晶結(jié)構(gòu)，或非結(jié)晶結(jié)構(gòu)。Because most common ceramics are crystalline, the definition of ceramic is often restricted to inorganic crystalline materials, as opposed to the non-crystalline glasses. 因?yàn)樵S多常見的陶瓷是結(jié)晶結(jié)構(gòu)，所以陶瓷的定義經(jīng)常局限于無機(jī)晶體材料，和非晶玻璃相反。Paragraph 2Ceramics h

52、ave been traditionally known as hard materials that can withstand harsh environments and high temperature. 傳統(tǒng)上認(rèn)為陶瓷是一種很硬的材料，它可以經(jīng)受住嚴(yán)酷的環(huán)境和高溫。 These attributes have lead to their use in applications such as cutting tools and turbine coatings. 這些屬性導(dǎo)致它們應(yīng)用于切削刀具和渦輪涂層。However, ceramics are also rich in elect

53、rical and magnetic properties, which have lead to their use as insulators, dielectrics, superconductors, magnets, electrodes, and electrolytes. 然而，陶瓷具有非常好的導(dǎo)電和磁性， 這使得它們被用作絕緣器，電介質(zhì)，超導(dǎo)材料，磁鐵，電極和電解質(zhì)。Paragraph 3Ceramics are used in the manufacture of knives. 陶瓷用于剪刀的制造The blade of a ceramic knife will stay

54、sharp for much longer than that of a steel knife, although it is more brittle and can be snapped by dropping it on a hard surface. 陶瓷刀片比鋼刀鋒利時(shí)間更長，盡管它更脆和落到硬表面時(shí)更易斷裂。Ceramics such as alumina and boron carbide have been used in ballistic armored vests to repel large-calibre rifle fire. 陶瓷諸如礬土和碳化硼應(yīng)經(jīng)被用于彈道盔

55、甲背心以阻擋大口徑步槍。Such plates are known commonly as small-arms protective inserts (SAPI). 這樣的盤子稱為輕兵器防護(hù)板。Similar material is used to protect cockpits of some military airplanes, because of the low weight of the material. 相似的材料被用于保護(hù)一些軍用飛機(jī)的駕駛室，由于材料較低的重量。Ceramic balls can be used to replace steel in ball bear

56、ings. 陶瓷球能夠用于替代球軸承中的鋼球。Their higher hardness means that they are much less susceptible to wear and can offer more than triple lifetimes. 它們更高的硬度意味著它們更不容易磨損，并且能夠提供三倍的壽命。They also deform less under load meaning they have less contact with the bearing retainer walls and can roll faster. 它們在負(fù)載下的變形更小，意味著

57、它們和軸承保持架的接觸更少，滾動(dòng)更快。In very high speed applications, heat from friction during rolling can cause problems for metal bearings; problems which are reduced by the use of ceramics. 在高速應(yīng)用中，滾動(dòng)過程中的摩擦熱能夠給金屬軸承造成問題，通過使用陶瓷，問題減少。Ceramics are also more chemically resistant and can be used in wet environments wher

58、e steel bearings would rust. 陶瓷化學(xué)抵抗力更強(qiáng)，能夠被用于潮濕環(huán)境中，在這樣的環(huán)境中鋼軸承將會(huì)生銹。The two major drawbacks to using ceramics is a significantly higher cost, and susceptibility to damage under shock loads. 使用陶瓷的兩個(gè)主要的缺陷是更高的成本，在沖擊載荷下容易損壞。In many cases their electrically insulating properties may also be valuable in bear

59、ings. 在許多情況下，它們的絕緣性質(zhì)在軸承中也是很有價(jià)值的。Paragraph 4In the early 1980s, Toyota researched production of an adiabatic ceramic engine which can run at a temperature of over 6000F (3300C). 在二十世紀(jì)80年代，Toyota研究了絕熱陶瓷引擎的生產(chǎn)，能夠在高于6000F (3300C)環(huán)境下運(yùn)轉(zhuǎn)。Ceramic engines do not require a cooling system and hence allow a majo

60、r weight reduction and therefore greater fuel efficiency. 陶瓷引擎不需要冷卻系統(tǒng)，因此降低重量，燃料效率更高。Fuel efficiency of the engine is also higher at high temperature. 引擎的燃料效率在高溫下更高。In a conventional metallic engine, much of the energy released from the fuel must be dissipated as waste heat in order to prevent a melt