《材料科学与工程专业外语》课程实施大纲

1、材料科学与工程专业外语课程实施大纲1、教学理念作为一名高校教师，在教学中注重“以学生为本”，重视研究性学习、探究性学习和协作性学习等现代教育理念的应用，以自己的“教”，来引导学生的“学”，对教学内容做精心取舍，以更好地培养学生的能力，努力成为学生的良师益友。在教学方法上，大力提倡“学生参与”，采取分组讨论、案例分析等多样的教学方式，努力调动学生的积极性，培养学习兴趣，激发学习热情，使学生充分地参与到整个学习活动中。本着“教学相长”的理念，对于学生提出的问题与质疑，认真对待，耐心解答。英语作为交流的工具，是一门应用性很强的学科，只有多听、多说、多读、多练才能真正掌握英语这一门语言。因此，在向学生

2、讲解与本专业有关的专业词汇外，对学生强调以多练作为学习的方法与手段也是必要的。2、课程介绍专业英语是大学英语教学的一个重要组成部分，它促进了学生从学习英语知识向专业应用英语知识的转变，也为三、四年级的本科生阅读专业领域的英语教科书、参考书及文献资料等奠定良好的基础。专业英语的教学不仅仅要培养学生的专业文献阅读能力，更要侧重学生科技英文写作能力及专业语言的交流能力，它是连接大学英语与双语教学的桥梁。本课程是高等学校本科材料和防腐类专业的必修课程，是学生在完成了英语基础阶段的学习任务后，需要修读的一门专业主干课。通过本课程的学习，使学生了解科技文献的基本结构和表达习惯，掌握与材料腐蚀相关的重要专业

3、词汇，培养学生熟练阅读专业文献和用英语进行科技论文翻译与写作的基本能力，提高学生的综合素质。学习本课程后，学生能掌握相当数量的专业词条和知识，了解专业科技英语及其翻译的特点，为进一步阅读本专业相关的英文书籍和文献，并将其译成通俗易懂的中文奠定坚实的基础。此外，还能掌握科技论文常用句式和大量专业词汇，可为专业领域内的英文摘要和论文撰写创造有利的条件。3、教师简介3.1 教师的职称、学历3.3研究兴趣（方向）无机功能材料的制备、表征与应用研究4、先修课程大学英语、无机化学、材料化学、物理化学、材料科学与工程5、课程目标本课程是材料及防腐专业的一门重要必修课。通过本课程的学习，使学生掌握相当数量的专

4、业词条和知识，了解专业科技英语及其翻译的特点，为进一步阅读本专业相关的英文书籍和文献，并将其译成通俗易懂的中文奠定坚实的基础。此外，学习本课程后，还能掌握科技论文常用句式和大量专业词汇，可为专业领域内的英文摘要和论文撰写创造有利的条件。6、课程内容内容要求及重点、难点学时安排Part 1 专业文献选讲Unit 1 Why do Metals Corrode?Unit 2 Corrosion and Its FormsUnit 3 Corrosion ControlUnit4 Polarization CurvesUnit 5 Electrochemical Impedance Spectros

5、copy进一步了解科技英语在文体、时态、词汇、句式等方面的特点提高专业文献阅读能力，长难句分析能力3. 掌握一些重要的专业英语词汇16学时Part 2英文科技论文的结构与写作Unit 6 How to Write a Scientific ArticleUnit 7 The Structure of an ArticleUnit 8 Style and LanguagePart Abstract掌握科技英语的特点，科技论文的结构以及写作技巧，常用句式等14学时7、课程实施7.1 Unit 1 Why do Metals Corrode?（1）教学目标掌握课后常用专业术语，科技英语翻译标准-确切

6、性；科技英语的翻译做到：明确、通顺、简练；翻译过程应做到深刻理解原文、确切表达译文、校核；了解金属腐蚀的原因和电化学腐蚀及其英文表达。（2）教学内容Corrosion is the disintegration of metal through an unintentional chemical or electrochemical action, starting at its surface. All metals exhibit a tendency to be oxidized, some more easily than others. A tabulation of the rel

7、ative strength of this tendency is called the galvanic series. Knowledge of a metals location in the series is an important piece of information to have in making decisions about its potential usefulness for structural and other applications.The driving force that causes metals to corrode is a natur

8、al consequence of their temporary existence in metallic form. To reach this metallic state from their occurrence in nature in the form of various chemical compounds (ores), it is necessary for them to absorb and store up for later return by corrosion, the energy required to release the metals from t

9、heir original compounds. The following pictures illustrate the similarity in color between pale green malachite, a common copper ore mineral, and the corrosion products on a brass plate (70% copper) exposed to a humid environment.The thermodynamic or chemical energy stored in a metal or that is free

10、d by its corrosion varies from metal to metal. It is relatively high for metals such as magnesium, aluminum, and iron, and relatively low for metals such as copper, silverand gold. Thefollowing Table lists a few metals in order of diminishing amounts of energy required to convert them from their oxi

11、des to metal. The high reactivity of magnesium and aluminum expressed as energy in Table 1.1 is paralleled by the special efforts that were historically required to transform these metals from their respective ores. The industrial process to produce aluminum metal on a large scale, for example, was

12、only invented at the end of the 19th centuryand objects made of this metal where still considered to be a novelty when the 2.85 kg aluminum cap was set as the last piece of the Washington Monumentin 1884.A typical cycle is illustrated by iron. The most common iron ore, hematite, is an oxide of iron.

13、 The most common product of the corrosion of iron, rust, has a similar chemical composition and color. The energy required to convert iron ore to metallic iron is returned when the iron corrodes to form the original compound. Only the rate of energy change may be different.The energy difference betw

14、een metals and their ores can be expressed in electrical terms that are in turn related to heats of formation of the compounds. The difficulty of extracting metals from their ores in terms of the energy required, and the consequent tendency to release this energy by corrosion, is reflected by the re

15、lative positions of pure metals in a list, which is discussed later as the electromotive series.（3) 教学过程及方法1）采用教师示范领读，翻译；学生诵读、翻译、教师点评两种方式；2）阐明科技英语与日常英语的差异。3）逐句分析句子结构，重点抓住“主、谓、宾”句子主干进行分析。（4) 作业安排掌握unit 1课后常用专业术语；翻译reading material 1第一段全部内容。（5) 参考文献Corrosion Basics: An Introduction, 2nd Edition, Pierr

16、e R. Roberge, by National Association of Corrosion Engineers, 2006.7.2 Unit 2 Corrosion and Its Forms（1）教学目标掌握课后常用专业术语，不同腐蚀类型的英文表达以及科技英语中的省略句，熟悉科技英语中的被动句、条件句、非谓语动词及介词短语。（2）教学内容2.1 What is corrosion?Corrosion is the gradual destruction of materials (usually metals) by chemical reaction with their env

17、ironment.In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen. Rusting, the formation of iron oxidesis a well-known example of electrochemical corrosion. This type of damage typically produces oxide(s) or salt(s) of the origina

18、l metal. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term degradation is more common. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids and gases.(Fr

19、om Wikipedia)2.2 Forms of corrosionIt is convenient to classify corrosion by the forms in which it manifests itself, the basis for this classification being the appearance of the corroded metal. Each form can be identified by mere visual observation. In most cases the naked eye is sufficient, but so

20、metimes magnification is helpful or required. Valuable information for the solution of a corrosion problem can often be obtained through careful observation of the corroded test specimens or failed equipment. Examination before cleaning is particularly desirable. Some of the eight forms of corrosion

21、 are unique, but all of them are more or less interrelated. The eight forms are:(1) Uniform, or general attack(2) Pitting(3) Crevice corrosion(4) Galvanic, or two-metal corrosion(5) Intergranularcorrosion(6) Dealloying, or selective leaching(7) Erosioncorrosion(8) StresscorrosionThe mentioned Module

22、s have introduced the general science of corrosion processes. In reality, the principles that govern these scientific concepts are rarely of interest to most people facing corrosion problems. The main questions these people generally ask are: How serious is the problem? How can it be fixed and how m

23、uchwill it cost? What caused the problem in the first place?The present Module will focus on answering the first of these questions and the next Module the last. Corrosion damage can take many shapes and forms that are often related to specific alloy/environment/operation conditions. The several for

24、ms of corrosion may be divided into three groups:1) Those recognizable with the unaided eye2) Those which are more easily discerned with specific aids (e.g. dye penetrants, magnetic particles, or low-power microscopy)3) Those which can only be identified definitely by optical or electronic microscop

25、yFig. 1.4 Main forms of corrosion attack regrouped by their ease of recognitionMuch can be deduced from examination of materials which have failed in service. It is often possible by visual examination to decide which corrosion mechanisms have been at work and what corrective measures are required t

26、o solve the problem. Below, the eight forms of corrosion are discussed in terms of their characteristics, mechanisms, and preventive measures.(1) Uniform corrosion, or general attackUniform corrosion is characterized by corrosive attack proceeding evenly over the entire surface area, or a large frac

27、tion of the total area. General thinning takes place until failure. On the basis of tonnage wastedwaster, this is the most important form of corrosion.However, uniform corrosion is relatively easily measured and predicted, making disastrous failures relatively rare. In many cases, it is objectionabl

28、e only from an appearance standpoint. As corrosion occurs uniformly over the entire surface of the metal component, it can be practically controlled by cathodic protection, use of coatings or paints, or simply by specifying a corrosion allowance. In other cases uniform corrosion adds color and appea

29、l to a surface. Two classics in this respect are the patina created by naturally tarnishing copper roofs and the rust hues produced on weathering steels.The breakdown of protective coating systems on structures often leads to this form of corrosion. Dulling of a bright or polished surface, etching b

30、y acid cleaners, or oxidation (discoloration) of steel are examples of surface corrosion. Corrosion resistant alloys and stainless steels can become tarnished or oxidized in corrosive environments. Surface corrosion can indicate a breakdown in the protective coating system, however, and should be ex

31、amined closely for more advanced attack. If surface corrosion is permitted to continue, the surface may become rough and surface corrosion can lead to more serious types of corrosion.(2) PittingPitting corrosion is a localized form of corrosion by which cavities or holes are produced in the material

32、. Pitting is considered to be more dangerous than uniform corrosion damage because itis more difficult to detect, predict and design against.Pitting is initiated by: 1) Localized chemical or mechanical damage to the protective oxide film; water chemistry factors which can cause breakdown of a passiv

33、e film are acidity, low dissolved oxygen concentrations (which tend to render a protective oxide film less stable) and high concentrations of chloride (as in seawater)2) Localized damage to, or poor application of, a protective coating 3) The presence of non-uniformities in the metal structure of th

34、ecomponent, e.g. nonmetallic inclusions.Mechanism:The driving power for pitting corrosion is the depassivation of a small area, which becomes anodic while an unknown but potentially vast area becomes cathodic, leading to very localized galvanic corrosion. The mechanism of pitting corrosion is probab

35、ly the same as crevice corrosion.The more conventional explanation for pitting corrosion is that it is an autocatalytic process. Metal oxidation results in localized acidity that is maintained by the spatial separation of the cathodic and anodic half-reactions, which creates a potential gradient and

36、 electromigration of aggressive anions into the pit.(3) Crevice corrosionCrevice corrosion is a localized form of corrosion usually associated with a stagnant solution on the micro-environmental level. Such stagnant microenvironments tend to occur in crevices (shielded areas) such as those formed un

37、der gaskets, washers, insulation material, fastener heads, surface deposits, disbonded coatings, threads, lap joints and clamps. Crevice corrosion is initiated by changes in local chemistry within the crevice: 1) Depletion of inhibitor in the crevice 2) Depletion of oxygen in the crevice 3) A shift

38、to acid conditions in the crevice4) Build-up of aggressive ion species (e.g. chloride) in the creviceAs oxygen diffusion into the crevice is restricted, a differential aeration cell tends to be set up between crevice (microenvironment) and the external surface (bulk environment). The cathodic oxygen

39、 reduction reaction cannot be sustained in the crevice area, giving it an anodic character in the concentration cell. This anodic imbalance can lead to the creation of highly corrosive micro-environmental conditions in the crevice, conducive to further metal dissolution. This results in the formatio

40、n of an acidic micro-environment, together with a high chloride ion concentration.The most common form is oxygen differential cell corrosion. This occurs because moisture has a lower oxygen content when it lies in a crevice than when it lies on a surface. The lower oxygen content in the crevice form

41、s an anode at the metal surface. The metal surface in contact with the portion of the moisture film exposed to air forms a cathode.(4) Galvanic, or two-metal corrosionGalvanic corrosion (also called dissimilar metal corrosion or wrongly electrolysis) refers to corrosion damage induced when two dissi

42、milar materials are coupled in a corrosive electrolyte.When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone. For galvanic corrosion to occur, three

43、conditions must be present:1) Electrochemically dissimilar metals must be present2) These metals must be in electrical contact, and3) The metals must be exposed to an electrolyteThe relative nobility of a material can be predicted by measuring its corrosion potential. The well-known galvanic series

44、lists the relative nobility of certain materials in sea water. A small anode/cathode area ratio is highly undesirable. In this case, the galvanic current is concentrated onto a small anodic area. Rapid thickness loss of the dissolving anode tends to occur under these conditions. Galvanic corrosion p

45、roblems should be solved by designing to avoid these problems in the first place.(5) Intergranular corrosionThe microstructure of metals and alloys is made up of grains, separated by grain boundaries. Intergranular corrosion is localized attack along the grain boundaries, or immediately adjacent to

46、grain boundaries, while the bulk of the grains remain largely unaffected. This form of corrosion is usually associated with chemical segregation effects (impuritieshave a tendency to be enriched at grain boundaries) or specific phases precipitated on the grain boundaries. Such precipitation can prod

47、uce zones of reduced corrosion resistance in the immediate vicinity.The attack is usually related to the segregation of specific elements or the formation of a compound in the boundary. Corrosion then occurs by preferential attack on the grain-boundary phase, or in a zone adjacent to it that has los

48、t an element necessary for adequate corrosion resistance -thus making the grain boundary zone anodic relative to the remainder of the surface. The attack usually progresses along a narrow path along the grain boundary and, in a severe case of grain-boundary corrosion;entire grains may be dislodged d

49、ue to complete deterioration of their boundaries. In any case the mechanical properties of the structure will be seriously affected.A classic example is the sensitization of stainless steels or weld decay. Chromium-rich grain boundary precipitates lead to a local depletion of Cr immediately adjacent

50、 to these precipitates, leaving these areas vulnerable to corrosive attack in certain electrolytes. Reheating a welded component during multi-pass welding is a common cause of this problem. In austenitic stainless steels, titanium or niobium can react with carbon to form carbides in the heat affecte

51、d zone (HAZ) causing a specific type of intergranular corrosion known as knife-line attack. These carbides build up next to the weld bead where they cannot diffuse due to rapid cooling of the weld metal. The problem of knife-line attack can be corrected by reheating the welded metal to allow diffusi

52、on to occur. Many aluminum base alloys are susceptible to intergranular corrosion on account of either phases anodic to aluminum being present along grain boundaries or due to depleted zones of copper adjacent to grain boundaries in copper-containing alloys.Alloys that have been extruded or otherwis

53、e worked heavily, with a microstructure of elongated, flattened grains, are particularly prone to this damage.(6)Dealloying, or selective leaching.Dealloying or selective leaching refers to the selective removal of one element from an alloy by corrosion processes. A common example is the dezincifica

54、tion of unstabilized brass, whereby a weakened, porous copper structure is produced.The selective removal of zinc can proceed in a uniform manner or on a localized (plug-type) scale. It is difficult to rationalize dezincification in terms of preferential Zn dissolution out of the brass lattice struc

55、ture. Rather,it is believed that brass dissolves with Zn remaining in solution and Cu replating out of the solution. Graphitic corrosion of gray cast iron, whereby a brittle graphite skeleton remains following preferential iron dissolution is a further example of selective leaching. The term graphit

56、ization is commonly used to identify this form of corrosion but is not recommended because of its use in metallurgy for the decomposition of carbide to graphite.During cast iron graphitic corrosion the porous graphite network, that makes up 4-5% of the total mass of the alloy, is impregnated with in

57、soluble corrosion products. As a result, the cast iron retains its appearance and shape but is weaker structurally. Testing and identification of graphitic corrosion is accomplished by scraping through the surface with a knife to reveal the crumbling of the iron beneath. Where extensive graphitic co

58、rrosion occurs, usually the only solution is replacement of the damaged element.(7) Erosion corrosionErosion corrosion is an acceleration in the rate of corrosion attack in metal due to the relative motion of a corrosive fluid anda metal surface. The increased turbulence caused by pitting on the int

59、ernal surfaces of a tube can result in rapidly increasing erosion rates and eventuallya leak. Erosion corrosion can also be aggravated by faulty workmanship. For example,burrs left at cut tube ends can upset smooth water flow, cause localized turbulence and high flow velocities, resulting in erosion

60、 corrosion. A combination of erosion andcorrosion can lead to extremely high pitting rates.Erosion-corrosion is most prevalent in soft alloys (i.e. copper, aluminum and lead alloys). Alloys which form a surface film in a corrosive environment commonly show a limiting velocity above which corrosion r