英语学习-《材料科学与工程专业英语》(DOC 38页)VIP专享VIP免费

第1页共37页编号：时间：2021年x月x日书山有路勤为径，学海无涯苦作舟页码：第1页共37页《材料科学与工程专业英语》Unit1MaterialsScienceandMetallurgicalEngineeringMaterialsareproperlymoredeep-seatedinourculturethanmostofusrealize.Trans-portation,housing,clothing,communication,recreationandfoodproduction--virtuallyeverysegmentofoureverydaylivesisinfluencedtoonedegreeoranotherbymaterials.Historically,thedevelopmentandadvancementofsocietieshavebeenintimatelytiedtothemembers'abilitiestoproduceandmanipulatematerialstofilltheirneeds.Infact,earlycivilizationshavebeendesignatedbytheleveloftheirmaterialsdevelopment(i.e.StoneAge,BronzeAge).Theearliesthumanshasaccesstoonlyaverylimitednumberofmaterials,thosethatoccurnaturallystone,wood,clay,skins,andsoon.Withtimetheydiscoveredtechniquesforproducingmaterialsthathadpropertiessuperiortothoseofthenaturalones:thesenewmaterialsincludedpotteryandvariousmetals.Furthermore,itwasdiscoveredthatthepropertiesofamaterialcouldbealteredbyheattreatmentsandbytheadditionofothersubstances.Atthispoint,materialsutilizationwastotallyaselectionprocess,thatis,decidingfromagiven,ratherlimitedsetofmaterialstheonethatwasbestsuitedforanapplicationbyvirtueofitscharacteristic.Itwasnotuntilrelativelyrecenttimesthatscientistscametounderstandtherelationshipsbetweenthestructuralelementsofmaterialsandtheirproperties.Thisknowledge,acquiredinthepast60yearsorso,hasempoweredthemtofashion,toalargedegree,thecharacteristicsofmaterials.Thus,tensofthousandsofdifferentmaterialshaveevolvedwithratherspecializedcharacteristicsthatmeettheneedsofourmodernandcomplexsociety.Thedevelopmentofmanytechnologiesthatmakeourexistencesocomfortablehasbeenintimatelyassociatedwiththeaccessibilityofsuitablematerials.Advancementintheunder--standingofamaterialtypeisoftentheforerunnertothestepwiseprogressionofatechnology.Forexample,automobileswouldnothavebeenpossiblewithouttheavailabilityofinexpensivesteelofsomeothercomparablesubstitutes.Inourcontemporaryera,sophisticatedelectronicdevicesrelyoncomponentsthataremadefromwhatarecalledsemiconductingmaterials.MaterialsScienceEngineeringMaterialsscienceisaninterdisciplinarystudythatcombineschemistry,physics,metallurgy,engineeringandveryrecentlylifesciences.Oneaspectofmaterialsscienceinvolvesstudyinganddesigningmaterialstomakethemusefulandreliableintheserviceofhumankind.Itstrivesforbasicunderstandingofhowstructuresandprocessesontheatomicscaleresultinthepropertiesandfunctionsfamiliarattheengineeringlevel.Materialsscientistsareinterestedinphysicalandchemicalphenomenaactingacrosslargemagnitudesofspaceandtimescales.Inthisregarditdiffersfromphysicsofchemistrywheretheemphasisismoreonexplainingthepropertiesofpuresubstances.Inmaterialssciencethereisalsoanemphasisondevelopingandusingknowledgetounderstandhowthepropertiesofmaterialscanbecontrollablydesignedbyvaryingthecompositions,structures,andthewayinwhichthebulkandsurfacesphasematerialsareprocessed.Incontrast,materialsengineeringis,onthebasisofthosestructurepropertiescorrelations,designingorengineeringthestructureofamaterialtoproduceapredeterminedsetofproperties.Inotherwords,materialsengineeringmainlydealswiththeuseofmaterialsindesignandhowmaterialsaremanufactured."Structure"isanebuloustermthatdeservessomeexplanation.Inbrief,the第2页共37页第1页共37页编号：时间：2021年x月x日书山有路勤为径，学海无涯苦作舟页码：第2页共37页s...