材料科学与工程专业英语课件.ppt

1、Hubei University of Automotive Hubei University of Automotive Hubei University of Automotive Hubei University of Automotive TechnologyTechnologyTechnologyTechnologySpecialty English 1 1、语法较为简单，多用被动语态，从句等。、语法较为简单，多用被动语态，从句等。2 2、专有名词多，有规律可循（构词法）（读音较、专有名词多，有规律可循（构词法）（读音较为复杂，无规律）为复杂，无规律）3 3、写作要求清晰明了、写作要

2、求清晰明了 如何学习？如何学习？（1 1）记忆常见科技词汇（构词法）记忆常见科技词汇（构词法）（2 2）多阅读科技文章，学习如何用英语表达。避）多阅读科技文章，学习如何用英语表达。避免自创的新奇语句。免自创的新奇语句。（3 3）课后练习翻译，写作（）课后练习翻译，写作（Practice makes Practice makes perfect.perfect.）Characteristics of Specialty EnglishChapter 1 Materials and Heat Treatment Reading and answer questionsThe new words y

3、ou maybe meet:metallic 金属的金属的corrosion 腐蚀腐蚀ductile 延展延展ball bearing 滚珠轴承滚珠轴承multiphase 多相多相wrought 加工的，精细的加工的，精细的malleable 可锻的可锻的 有延展性的有延展性的Ferrous AlloysArbitrary 专横的，独断的，任意的Smelt 熔炼，精炼Intricate 复杂的，精巧的Combination 结合，合并，化合物Ferrous AlloysMore than 90%by weight of the metallic materials used by human

4、 beings are ferrous alloys.This represents an immense family of engineering materials with a wide range of microstructure and related properties.Ferrous AlloysThe majority of engineering designs that require structural load support or power transmission involve ferrous alloys.as a practical matter,t

5、hese alloys fall into two broad categories based on the carbon in the alloy composition.Ferrous AlloysSteel generally contains between 0.05w and 2.0 w carbon.The cast irons generally contain between 2.0w and 4.5 w carbon.Within the steel category,we shall distinguish whether or not a significant amo

6、unt of alloying elements other than carbon is used.对于钢的区分，我们要弄清楚的是是否含有有效量的合金元素而不是对于钢的区分，我们要弄清楚的是是否含有有效量的合金元素而不是碳的含量。碳的含量。Ferrous AlloysFerrous AlloysA composition of 5 w total noncarbon additions will serve as an arbitrary boundary between low alloy and high alloy steels.Ferrous AlloysThese alloy ad

7、ditions are chosen carefully because they invariably bring with them sharply increased material costs.They are justified only by essential improvements in properties such as higher strength or improved corrosion resistancequestionsHow do you distinguish steel from cast iron?How do you distinguish lo

8、w alloy steel from high alloy steel?1.1.1 Iron and Steel The earth contains a large number of metals which are useful to man.One of the most important of these is iron.Modern industry needs considerable quantities of this metal,either in the form of iron or in the form of steel.1.1.1 Iron and SteelA

9、 certain number of non-ferrous metals,including aluminum and zinc,are also important,but even today the majority of our engineering products are of iron or steel.Moreover,iron possesses magnetic properties,which have made the development of electrical power possible.1.1.1 Iron and SteelThe iron ore

10、which we find on earth is not pure.It contains some impurities that must be removed by smelting.The process of smelting consists of heating the ore in a blast furnace with coke and limestone,and reducing it to metal.Blasts of hot air enter the furnace from the bottom and provide the oxygen that is n

11、ecessary for the reduction of the ore.1.1.1 Iron and SteelThe ore becomes molten,and its oxides combine with carbon from the coke.The non-metallic constituents of the ore combine with the limestone to form a liquid slag.This floats on top of the molten iron,and passed out of the furnace through a ta

12、p.The metal which remains is pig iron.1.1.1 Iron and SteelWe can melt this down again in another furnace-a cupola-with more coke and limestone,and tap it out into a ladle or directly into molds.This is cast iron.Cast iron does not have the strength of steel.It is brittle and may fracture under tensi

13、on.1.1.1 Iron and SteelBut it possesses certain properties that make it very useful in the manufacture of machinery.In the molten state it is very fluid,therefore,it is easy to cast it into intricate shapes.Also it is easy to machine it.Cast iron contains small proportion of other substances.1.1.1 I

14、ron and SteelThese non-metallic constituents of cast iron include carbon,silicon and sulphur,and the presence of these substances affects the behavior of the metal.Iron which contains a negligible quantity of carbon,for example,wrought iron behaves differently from iron which contains a lot of carbo

15、n.1.1.1 Iron and SteelThe carbon in cast iron is present partly as free graphite and partly as a chemical combination of iron and carbon which is called cementite.This is a very hard substance,and it makes the iron hard too.1.1.1 Iron and SteelHowever,iron can only hold about 1.5%of cementite.Any ca

16、rbon content above that percentage is present of the form of a flaky graphite.1.1.1 Iron and SteelSteel contains no free graphite,and its carbon content ranges from almost nothing to 1.5%.We make wire and tubing from mild steel with a very low carbon content,and drills and cutting tools from high carbon steel.questionsHow is the steel made?If you want to have a high strength iron based material,what should you do?What is the function of the coke when producing pig iron?What is the difference bet