电梯专业英语课件03---金属知识.pptx

1、Whats metal?,(什么是金属?),How many kinds of metal?金属如何划分，有哪些种类？,Whats metal?(什么是金属?),Metals were formerly thought to be those elements that had a metallic luster and were good conductors of heat and electricity.Actually,metals are generally defined as those elements whose hydroxides form bases（such as s

2、odium or potassium）.金属过去被认为是具有金属光泽、良好的导电性和导热性 的物质。实际上，金属一般被定义为其氢氧化物为碱性的物质（如 钠、钾）,Clpausresmifeitacl ationo纯f 金M属etals(金属分类),alloy 合金Metals may exist as pure elements.When two or more metallic elements are combined,they form a mixture called an alloy.金属可以是由单一元素构成的纯金属，也可以是由两 种或两种以上金属元素组成的化合物，这种化合物就称为

3、合金。,Cfelrarosuss mifeitcalas tion of铁a基ll合o金y(合金分类),nonferrous metals 非铁基合金Alloys may be further classified as ferrous and nonferrous.Ferrous alloys contain iron.Nonferrous alloys do not contain iron.合金又可细分为铁合金和非铁合金，其区别就在于是 否包含铁元素。,iron-carbon alloybronzebrassphosphor bronzestainless steel,铁碳合金青铜黄铜磷

4、(青)铜不锈钢,DoPyroou pkneowrtsioemse oprfopMertieestoaf lmset(a金ls？属特性)你知道金属的一些特性吗？Strength 强度Metals have properties that distinguish them from other materials.The most important of these properties is strength,or the ability to support weight without bending or breaking.金属具有很多区别于其他材料的特性。其中最重要的就 是强度，它是一

5、种承受载荷不发生弯折或断裂的能力。,Properties of Metals(金属特性),The properties of metals may be classified in three,categories:chemical properties,mechanical properties,and physical properties.金属的特性可以分为三类:即化学特性、机械特性和物理 特性。,),Heat treHatmeeanttis ta rpaertaoftmmetaellunrgty.It(c热han处ges t理he structures of metals by the

6、 application of heat.,热处理是冶金学的一部分，通过加热改变了金属的结构。,hardeningtemperingannealingnormalizing,淬火回火退火正火,Machinetool(机床),Broadly speaking,the purpose of all machine tools is to produce metal parts by changing the shape,size,or finish of a piece of material.一般来讲，机床的使用目的就在于通过改变毛坯的形状、大小或材料表面光洁度等，使之成为机器零件。Do you

7、 know some machine tool?你知道的机床有哪些？,lathes,drilling machines planers milling machines grinding machines,Machinetool(机床),车床,钻床 刨床 铣床 磨床,Sentence explanation(句型讲解),Grinding is one of the most accurate of all the basic machining methods.磨床所能达到的加工精度是所有的机加工方法中最高的。In understanding the related areas of meta

8、lworking and methods used today,the mechanical properties of metals are of the utmost importance.在了解金属加工的相关领域以及目前所采用的加工方法 时，金属机械特性就显得尤其重要。,Sentence explanation(句型讲解),The maximum degree of hardness obtainable in steel by direct hardening is determined largely by the carbon content.直接冷却后的钢所能获得的最大硬度在很大

9、程度上是由 碳的含量所决定In metallurgy it is a substance,with metallic properties,that is composed of two or more elements,intimately mixed.在冶金学中，合金是由两种或两种以上的元素均匀混合、具有金属特性的物质。,Sentence explanation(句型讲解),The hardness that can be obtained from a given,treatment depends upon the following three factors:quenching r

10、ate,carbon content and work-piece size.通过热处理可获得的硬度主要与以下三方面的因素有关:淬火速度,碳的含量,工件的尺寸。Metals also possess another important property recycling and reuse.回收再利用是金属的另一个很重要的性质。,1.参考第E4x4e页r倒ci数s第e二A段n和a第ly三s段is。(退习火可题以释分放析内部)应变 和应力，有完全退火、低温退火和球化退火三种。,B2.参考第42页倒数第一段。强度时一种承受载荷而不发生弹 性变形或破裂的能力。A3.参考第43页倒数第三段。金属特性可以分为：化学特性、机械特性和物理特性。（不分顺序）A,C,B4.参考第43页倒数第五段。热处理通过加热改变金属结构。C,5.参考第E4x6e页r倒ci数s第e二A段n。a磨ly床s能is达(到习的加题工精分度析是所)有 加工方法中最高的。,Exercise Analysis(习题分析),7.,hydroxide,参考第41页第二段。metal,参考第41页第三段。strength,toughness，参考第42页最后一段。4）water,参考第43页倒数第二段。5）normalizing,参考第44页最后一段。6）lathe，参考第44页最后一段。,谢谢！,