材料专业英语课件

HubeiUniversityofAutomotiveTechnologySpecialtyEnglish1、语法较为简单，多用被动语态，从句等。2、专有名词多，有规律可循（构词法）（读音较为复杂，无规律）3、写作要求清晰明了如何学习？（1）记忆常见科技词汇（构词法）（2）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。（3）课后练习翻译，写作（Practicemakesperfect.）★CharacteristicsofSpecialtyEnglishChapter1MaterialsandHeatTreatmentMechanicalEngineeringmaterialsMetallicMaterialsFerrousalloysCastironCarbonSteelAlloysteelnon-ferrousalloysAluminumalloyscopperalloysothers:magnesiumalloys;Titaniumalloys;Nickelalloys;LeadalloysOrganicpolymermaterialsplasticrubberSyntheticFibersInorganicnon-metallicmaterialsTraditionalceramicsSpecialCeramicsCompositeMaterialsMetalMatrixCompositesPolymerMatrixCompositesCeramicMatrixComposites◆ReadingandanswerquestionsThenewwordsyoumaybemeet:metallic金属的corrosion腐蚀ductile延展ballbearing滚珠轴承multiphase多相wrought加工的，精细的malleable可锻的有延展性的FerrousAlloysArbitrary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FerrousAlloysMorethan90%byweightofthemetallicmaterialsusedbyhumanbeingsareferrousalloys.Thisrepresentsanimmensefamilyofengineeringmaterialswithawiderangeofmicrostructureandrelatedproperties.FerrousAlloysThemajorityofengineeringdesignsthatrequirestructuralloadsupportorpowertransmissioninvolveferrousalloys.asapracticalmatter,thesealloysfallintotwobroadcategoriesbasedonthecarboninthealloycomposition.FerrousAlloysSteelgenerallycontainsbetween0.05wand2.0wcarbon.Thecastironsgenerallycontainbetween2.0wand4.5wcarbon.Withinthesteelcategory,weshalldistinguishwhetherornotasignificantamountofalloyingelementsotherthancarbonisused.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。FerrousAlloysFerrousAlloysAcompositionof5wtotalnoncarbonadditionswillserveasanarbitraryboundarybetweenlowalloyandhighalloysteels.FerrousAlloysThesealloyadditionsarechosencarefullybecausetheyinvariablybringwiththemsharplyincreasedmaterialcosts.TheyarejustifiedonlybyessentialimprovementsinpropertiessuchashigherstrengthorimprovedcorrosionresistancequestionsHowdoyoudistinguishsteelfromcastiron?Howdoyoudistinguishlowalloysteelfromhighalloysteel?1.1.1IronandSteelTheearthcontainsalargenumberofmetalswhichareusefultoman.Oneofthemostimportantoftheseisiron.Modernindustryneedsconsiderablequantitiesofthismetal,eitherintheformofironorintheformofsteel.1.1.1IronandSteelAcertainnumberofnon-ferrousmetals,includingaluminumandzinc,arealsoimportant,buteventodaythemajorityofourengineeringproductsareofironorsteel.Moreover,ironpossessesmagneticproperties,whichhavemadethedevelopmentofelectricalpowerpossible.1.1.1IronandSteelTheironorewhichwefindonearthisnotpure.Itcontainssomeimpuritiesthatmustberemovedbysmelting.Theprocessofsmeltingconsistsofheatingtheoreinablastfurnacewithcokeandlimestone,andreducingittometal.Blastsofhotairenterthefurnacefromthebottomandprovidetheoxygenthatisnecessaryforthereductionoftheore.1.1.1IronandSteelTheorebecomesmolten,anditsoxidescombinewithcarbonfromthecoke.Thenon-metallicconstituentsoftheorecombinewiththelimestonetoformaliquidslag.Thisfloatsontopofthemolteniron,andpassedoutofthefurnacethroughatap.Themetalwhichremainsispigiron.1.1.1IronandSteelWecanmeltthisdownagaininanotherfurnace-acupola-withmorecokeandlimestone,andtapitoutintoaladleordirectlyintomolds.Thisiscastiron.Castirondoesnothavethestrengthofsteel.Itisbrittleandmayfractureundertension.1.1.1IronandSteelButitpossessescertainpropertiesthatmakeitveryusefulinthemanufactureofmachinery.Inthemoltenstateitisveryfluid,therefore,itiseasytocastitintointricateshapes.Alsoitiseasytomachineit.Castironcontainssmallproportionofothersubstances.1.1.1IronandSteelThesenon-metallicconstituentsofcastironincludecarbon,siliconandsulphur,andthepresenceofthesesubstancesaffectsthebehaviorofthemetal.Ironwhichcontainsanegligiblequantityofcarbon,forexample,wroughtironbehavesdifferentlyfromironwhichcontainsalotofcarbon.1.1.1IronandSteelThecarbonincastironispresentpartlyasfreegraphiteandpartlyasachemicalcombinationofironandcarbonwhichiscalledcementite.Thisisaveryhardsubstance,anditmakestheironhardtoo.1.1.1IronandSteelHowever,ironcanonlyholdabout1.5%ofcementite.Anycarboncontentabovethatpercentageispresentoftheformofaflakygraphite.1.1.1IronandSteelSteelcontainsnofreegraphite,anditscarboncontentrangesfromalmostnothingto1.5%.Wemakewireandtubingfrommildsteelwithaverylowcarboncontent,anddrillsandcuttingtoolsfromhighcarbonsteel.questionsHowisthesteelmade?Ifyouwanttohaveahighstrengthironbasedmaterial,whatshouldyoudo?Whatisthefunctionofthecokewhenproducingpigiron?Whatisthedifferencebetweenthepigironandthecastiron?1.1.2CarbonandlowalloysteelThemajorityofferrousalloysbelongstothiscategory.Thereasonsforthisarestraightforward.Theyaremoderatelypricedduetotheabsenceoflargeamountsofalloyingelements,andtheyaresufficientlyductiletobereadilyformed.Thefinalproductisstronganddurable.Theseeminentlypracticalmaterialsfindapplicationfromballbearingstometalsheetformedintoautomobilebodies.Forexample,the10XX,11XX,12XX,15XXetc.(AISIstandards,inwhichthefirsttwonumbersgiveacodedesignatingthetypeofalloyadditionsandthelasttwoorthreenumbersgivethecarboncontentinhundredthsofa