材料科学与工程专业英语-(1)

材料科学与工程专业英语材料专业英语翻译主讲：林建国材料专业英语课程简介：•课堂6学时，课后14学时•考试：开卷，当堂完成材料专业英语主要内容及课时安排•Introductiontomaterialsscienceandengineering(4学时)•Metallicmaterialsandalloys（4学时）•Ceramics（2学时）•Composites（2学时）•Nanostructuredmaterials（2学时）材料专业英语Part1Introductiontomaterialsscienceandengineering•Unit1Physicalandchemicalpropertiesofmaterials•Unit2Mechanicalpropertiesofmaterials材料专业英语Unit1Physicalandchemicalpropertiesofmaterials•Physicalpropertiesarethosethatcanbeobservedwithoutchangingtheidentityofthesubstance.Thegeneralpropertiesofmattersuchascolor,density,hardness,areexamplesofphysicalproperties.Propertiesthatdescribehowasubstancechangesintoacompletelydifferentsubstancearecalledchemicalproperties.Flammabilityandcorrosion/oxidationresistanceareexamplesofchemicalproperties.材料专业英语•Ingeneral,someofthemoreimportantphysicalandchemicalpropertiesfromanengineeringmaterialstandpointincludephasetransformationtemperatures,density,specificgravity,thermalconductivity,linearcoefficientofthermalexpansion,electricalconductivityandresistivity,magneticpermeability,andcorrosionresistance,andsoon.磁导率材料专业英语PhaseTransformationTemperatures•Whentemperaturerisesandpressureisheldconstant,atypicalsubstancechangesfromsolidtoliquidandthentovapor.Transitionsfromsolidtoliquid,fromliquidtovapor,fromvaportosolidandvisaversaarecalledphasetransformationsortransitions.Sincesomesubstanceshaveseveralcrystalforms,technicallytherecanbesolidtoanothersolidfromphasetransformation.材料专业英语Meltingpoint:thephasetransitiontemperaturewhereasolidchangestoaliquidBoilingpoint:thetemperatureatwhichthevaporpressureofaliquidequals1atm(101.3kPa)材料专业英语Somematerials,suchasmanypolymers,donotgosimplyfromasolidtoaliquidwithincreasingtemperature.Instead,atsometemperaturebelowthemeltingpoint,theystarttolosetheircrystallinestructurebutthemoleculesremainlinkedinchains,whichresultsinasoftandpliablematerial.Thetemperatureatwhichasolid,glassymaterialbeginstosoftenandflowiscalledtheglasstransitiontemperature.材料专业英语Density•Masscanbethinlydsitrbutedasinapillow,ortightlypackedasinablockoflead.•质量可以像枕头似地稀疏地分布，也可以像铅那样紧紧地堆积在一起。•Thespacethemassoccupiesisitsvolume,andthemassperunitofvolumeisitsdensity.材料专业英语•Mass(m)isafundamentalmeasureoftheamountofmatter.Weight(w)isameasureoftheforceexertedbyamassandthisforceisproducedbytheaccelerationofgravity.•Therefore,onthesurfaceofearth,themassofanobjectisdeterminedbydividingtheweightofanobjectby9.8m/s2(theaccelerationofgravityonthesurfaceoftheearth).因此，在地球表面，物体的质量由物体的重量和重力加速度所决定。Sincewearetypicallycomparingthingsonthesurfaceoftheearth,theweightofanobjectiscommonlyusedratherthancalculatingitsmass.材料专业英语•Thedensity(r)ofamaterialdependsonthephaseitisinandthetemperature(thedensityofliquidsandgasesisverytemperaturedependent).Waterintheliquidstatehasadensityof1g/cm3at4℃.Icehasadensityof0.9171g/cm3at0℃,anditshouldbenotedthatthisdecreaseindensityforthesolidphaseisunusual.Foralmostallothersubstances,thedensityofthesolidphaseisgreaterthanthatoftheliquidphase.Watervaporhasadensityof0.051g/cm3.材料专业英语SpecificGravity•Specificgravityistheratioofdensityofasubstancecomparedtothedensityoffreshwaterat4℃.Atthistemperaturethedensityofwaterisatitsgreatestvalueandequalto1g/mL.•Sincespecificgravityisaratio,soithasnounits.Anobjectwillfloatinwaterifitsdensityislessthanthedensityofwaterandsinkifitsdensityisgreaterthanthatofwater.材料专业英语•Similarly,anobjectwithspecificgravitylessthan1willfloatandthosewithaspecificgravitygreaterthan1willsink.•SpecificgravityvaluesforafewcommonsubstancesareAu,19.3;mercury,13.6;alcohol,0.7893;benzene,0.8786.•Notethatsincewaterhasdensityof1g/cm3,thespecificgravityisthesameasthedensityofthematerialmeasureding/cm3.材料专业英语MagneticPermeability•Magneticpermeabilityorsimplypermeabilityistheeasewithwhichamaterialcanbemagnetized.Itisaconstantofproportionalitythatexistsbetweenmagneticinductionandmagneticfieldintensity.磁感应强度磁场强度材料专业英语•Thisconstantisequaltoapproximately1.257×10-6Henrypermeter(H/m)infreespace(avacuum).Inothermaterialsitcanbemuchdifferent,oftensubstantiallygreaterthanthefree-spacevalue,whichissymbolized0.•其他材料却截然不同，通常远大于真空值。材料专业英语•Materialsthatcausethelinesoffluxtomovefartherapart,resultinginadecreaseinmagneticfluxdensitycomparedwithavacuum,arecalleddiamagnetic.Materialsthatconcentratemagneticfluxbyafactorofmorethanonebutlessthanorequaltotenarecalledparamagnetic;materialsthatconcentratethefluxbyafactorofmorethantenarecalledferromagnetic.Thepermeabilityfactorsofsomesubstanceschangewithrisingorfallingtemperature,orwiththeintensityoftheappliedmagneticfield.材料专业英语Exercises•TranslatethefollowingintoChinesePhasetransformationtemperaturesSpecificgravityThermalconductivityThemeltingpointTheaccelerationofgravityMagneticpermeabilityMagneticlinesoffluxferromagnetic材料专业英语Unit2MechanicalPropertiesofMaterials•Themechanicalpropertiesofamaterialarethoseonesthatinvolveareactiontoanappliedload.•Thecommonpropertiesconsideredarestrength,ductility,hardness,impactresistance,andfracturetoughness.强度、延展性、硬度、冲击强度、断裂韧性材料专业英语•Moststructuralmaterialsareanisotropic,whichmeansthattheirmaterialp