機(jī)械工程英語(yǔ)翻譯

1、本文格式為Word版，下載可任意編輯 機(jī)械工程英語(yǔ)翻譯 機(jī)械工程英語(yǔ)其次版葉邦彥陳統(tǒng)堅(jiān)主編 Unit1 Advanced engineering materials Types of Materials 材料的類(lèi)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 liv

2、ing) materials. 材料可以按多種方法分類(lèi)?？茖W(xué)家常根據(jù)狀態(tài)將材料分為：固體、液體或氣體。他們也把材料分為有機(jī)材料(曾經(jīng)有生命的)和無(wú)機(jī)材料(從未有生命的)。 For industrial purposes, materials are pided into engineering materials or nonengineering materials. Engineering materials are those used in manufacture and become parts of products. 就工業(yè)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

3、造并成為產(chǎn)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(xué)品、燃料、潤(rùn)滑劑以及其它用于加工制造過(guò)程但不成為產(chǎn)品組成部分的材料。 Engineering materials may be further subpided into: Metal Ceramics Composite P

4、olymers, etc. 工程材料還能進(jìn)一步細(xì)分為：金屬材料陶瓷材料復(fù)合材料聚合材料，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. 金屬就是尋常具有良好導(dǎo)電性和導(dǎo)熱性的元素。大量金屬具有高強(qiáng)度、高硬度以及良好的延展性。Some metals, such as ir

5、on, 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(zhuǎn)變成超導(dǎo)體。 What is the difference between an alloy and a pure metalT Pure metals are elements which come from a particular area of the periodic t

6、able. 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(qū)別是什么？純金屬是在元素周期表中占據(jù)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. Exampl

7、es 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(zhì)能通過(guò)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，以及金飾品尋常含有金鎳合金。 Why are metals and alloys usedT Many metals and alloys have high d

8、ensities and are used in applications which require a high mass-to-volume ratio. 為什么要使用金屬和合金？大量金屬和合金具有高密度，因此被用在需要較高質(zhì)量體積比的場(chǎng)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,

9、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?xún)€約燃料。大量合金還具有高斷裂韌性， 1 這意味著它們能經(jīng)得起沖擊并且是耐用的。 What are some important properties of metalsT Density is defined as a materials mass pided by its volume. Most metals have relatively high densities, especially compared to poly

10、mers. 金屬有哪些重要特性？ 密度定義為材料的質(zhì)量與其體積之比。大多數(shù)金屬密度相對(duì)較高，特別是和聚合物相對(duì)比而言。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

11、also require low weight. 高密度材料尋常由較大原子序數(shù)原子構(gòu)成，例如金和鉛。然而，諸如鋁和鎂之類(lèi)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(chǎng)合。 Fracture toughness can be described as a materials ability to avoid fracture, especially when a flaw is introduced. Metals can generally contain nicT and dents without weakening very much, and are impact re

12、sistant. A football player counts on this when he trusts that his facemask wont shatter. 斷裂韌性可以描述為材料防止斷裂特別是出現(xiàn)缺點(diǎn)時(shí)不斷裂的能力。金屬一般能在有缺口和凹痕的狀況下不顯著減弱，并且能抗?fàn)帥_擊。橄欖球運(yùn)動(dòng)員據(jù)此相信他的面罩不會(huì)裂成碎片。 Plastic deformation is the ability of bend or deform before breaking. As engineers, we usually design materials so that they dont

13、 deform under normal conditions. You dont 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(shè)計(jì)時(shí)尋常要使材料在正常條件下不變形。沒(méi)有人樂(lè)意一陣猛烈的西風(fēng)過(guò)后自己的汽車(chē)向東傾斜。 However, sometimes we can take advantage of plastic deformation. The crumple zones in a car absorb energy by undergoing plastic d

14、eformation before they break. 然而，有時(shí)我們也能利用塑性變形。汽車(chē)上壓皺的區(qū)域在它們斷裂前通過(guò)經(jīng)歷塑性變形來(lái)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

15、cooking pans and electrical wires. 金屬的原子連結(jié)對(duì)它們的特性也有影響。在金屬內(nèi)部，原子的外層階電子由所有原子共享并能四處自由移動(dòng)。由于電子能導(dǎo)熱和導(dǎo)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. 由于這些階電子吸收到達(dá)金屬的光子，所以透過(guò)金屬不可能看得見(jiàn)。沒(méi)有光子能通過(guò)金屬。

16、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(qiáng)度、斷裂韌性、塑性變形、導(dǎo)電性以及環(huán)境侵蝕。 For example, adding a small amount of ir

17、on 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(qiáng)。同樣，在鋼里加一些鉻能減緩它的生銹過(guò)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 materialBy this definition, c

18、eramic materials would also include glasses; however, many materials scientists add the stipulation that “ceramicmust also be crystalline. 陶瓷尋常被概括地定義為無(wú)機(jī)的非金屬材料。照此定義，陶瓷材料也應(yīng)包括玻璃；然而大量材料科學(xué)家添加了“陶瓷務(wù)必同時(shí)是晶體物組成的約定。 A glass is an inorganic nonmetallic material that does not have a crystalline structure. Such m

19、aterials are said to be amorphous. 玻璃是沒(méi)有晶體狀結(jié)構(gòu)的無(wú)機(jī)非金屬材料。這種材料被稱(chēng)為非結(jié)晶質(zhì)材料。 2 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(diǎn)、低密度、高強(qiáng)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 s