1、PEC材料工程英語證書考試-材料試驗詞匯AAdherenceTheextenttowhichacoatingbondstoasubstrate.AdherenceIndex-MeasureoftheAdherenceofporcelainenamelandceramiccoatingstosheetmetal.AlphaRockwellHardnessIndexoftheresistanceofaplastictosurfacepenetrationbyaspecifiedindenterunderspecifiedloadappliedwithaRockwellHardnesstester.

2、HighervaluesindicatehigherindentationHardness.AxialStrainTheStraininthedirectionthattheloadisapplied,oronthesameaxisastheappliedload.AnalogueboardAmachinecircuitboard,whichconvertsanaloguesignalsintodigitalsignal.AnchorPinAsteelpinthatconnectsagriporjigtoaneyeendAutoReturnAutoReturn,whensettoon,caus

3、esthecrossheadtoreturnautomaticallytoitsZeropointattheendofthetest.BBendTestMethodformeasuringDuctilityofcertainmaterials.Therearenostandardizedtermsforreportingbendtestresultsforbroadclassesofmaterials;rather,termsassociatedwithbendtestsapplytospecificformsortypesofmaterials.Forexample,materialsspe

4、cificationssometimesrequirethataspecimenbebenttoaspecifiedinsidediameter(ASTMA-360,steelproducts).AbendtestforDuctilityofweldsisgiveninASTME-190.Resultsoftestsoffiberboardarereportedbyadescriptionofthefailureorphotographs.BendingStrengthAlternatetermforFlexuralStrength.Itismostcommonlyusedtodescribe

5、flexurepropertiesofcastironandwoodproducts.BondStrengthStress(tensileloaddividedbyareaofbond)requiredtoruptureabondformedbyanadhesivebetweentwometalblocks.BreakElongationTheElongationofthespecimentothebreakpoint.BreakingLoadLoadwhichcausesfractureinatensile,compression,flexureorTorsionTest.Intensile

6、testsoftextilesandyarns,breakingloadalsoiscalledbreakingstrength.Intensiletestsofthinsheetmaterialsormaterialsinformofsmalldiameterwireitisdifficulttodistinguishbetweenbreakingloadandthemaximumloaddeveloped,sothelatterisconsideredthebreakingload.BreakingStrengthStressrequiredrupturingthespecimen.GLO

7、SSARYOFMATERIALSTESTINGBulkModulusofElasticityRatioofStresstochangeinvolumeofamaterialsubjectedtoaxialloading.RelatedtoModulusofElasticity(E)andPoisson'sRatio(r)bythefollowingequation:BulkModulusK=E/3(1-2r).CleavageStrengthTensileloadrequiredtocauseseparationofa1-in.longmetal-to-metaladhesivebon

8、dundertheconditionssetinASTMD-1062.ClimbingDrumPeelTestMethodfordeterminingPeelResistanceofadhesivebondbetweenarelativelyflexibleandarigidmaterial.(ASTMD-1781).CoefficientofElasticityAnalternatetermforModulusofElasticity.CohesiveStrengthTheoreticalStressthatcausesfractureintensiletestifmaterialexhib

9、itsnoplasticdeformation.ComplexModulusMeasureofdynamicmechanicalpropertiesofamaterial,takingintoaccountenergydissipatedasheatduringdeformationandRecovery.Itisequaltothesumofstaticmodulusofamaterialanditslossmodulus.Inthecaseofshearloading,itiscalleddynamicmodulus.CompressibilityExtenttowhichamateria

10、liscompressedintestforcompressibilityandRecoveryofgasketmaterials.ItisusuallyreportedwithRecovery.CompressibilityandRecoveryTestMethodformeasuringbehaviorofgasketmaterialsundershorttimecompressiveloadingatroomtemperature.ASTMF-36outlinesastandardprocedure.Thistestisnotdesignedtoindicatelongterm(cree

11、p)behaviorandshouldnotbeconfusedwiththeplastometertest.CompressionTypicallyadirectionofforceappliedtoasampletodecreaseitsheightCompressionFatigueAbilityofrubbertosustainrepeatedfluctuatingcompressiveloads.(ASTMD-623)CompressionsetTheextenttowhichrubberispermanentlydeformedbyaprolongedcompressiveload

12、(ASTMD-395).Shouldnotbeconfusedwithlowtemperaturecompressionset.CompressiontestMethodfordeterminingbehaviorofmaterialsundercrushingloads.Specimeniscompressed,anddeformationatvariousloadsisrecorded.Compressivestressandstrainarecalculatedandplottedasastress-straindiagramwhichisusedtodetermineelasticli

13、mit,proportionallimit,yieldpoint,YieldStrengthand(forsomematerials)compressivestrength.StandardcompressiontestsaregiveninASTMC-773(highstrengthceramics),ASTME-9(metals),ASTME-209(metalsatelevatedtemperatures)andASTMD-695(plastics).Compression-DeflectionTestNondestructivemethodfordeterminingrelations

14、hipbetweencompressiveloadanddeflectionunderloadforspecimenCompressiveDeformation-ExtenttowhichamaterialdeformsunderaCrushingLoad.CompressiveStrengthMaximumstressamaterialcansustainundercrushloading.Compressivestrengthiscalculatedbydividingthemaximumloadbytheoriginalcross-sectionalareaofaspecimeninac

15、ompressiontest.CompressiveYieldStrengthStresswhichcausesamaterialtoexhibitaspecifieddeformation.Usuallyitisdeterminedfromthestress-straindiagramobtainedinacompressiontest.CreepDeformationthatoccursoveraperiodoftimewhenamaterialissubjectedtoconstantstressatconstanttemperature.Inmetals,creepusuallyocc

16、ursonlyatelevatedtemperatures.Creepatroomtemperatureismorecommoninplasticmaterialsandiscalledcoldflowordeformationunderload.Dataobtainedinacreeptestusuallyispresentedasaplotofcreepvs.timewithstressandtemperatureconstant.SlopeofthecurveiscreeprateandendpointofthecurveisTimeforRupture.Asindicatedinthe

17、accompanyingdiagram,thecreepofamaterialcanbedividedintothreestages.Firststage,orprimarycreep,startsatarapidrateandslowswithtime.Secondstage(secondary)creephasarelativelyuniformrate.Thirdstage(tertiary)creephasanacceleratingcreeprateandterminatesbyfailureofmaterialatTimeforRupture.CreepLimitAlternate

18、termforCreepStrength.CreepRateTimerateofdeformationofamaterialsubjecttoStressataconstanttemperature.Itistheslopeofthecreepvs.timediagramobtainedinacreeptest.Unitsusuallyarein/in/hror%ofelongation/hr.Minimumcreeprateistheslopeoftheportionofthecreepvs.timediagramcorrespondingtosecondarycreep.CreepReco

19、veryRateofdecreaseindeformationthatoccurswhenloadisremovedafterprolongedapplicationinaCreepTest.Constanttemperatureismaintainedtoeliminateeffectsofthermalexpansion,andmeasurementsaretakenfromtimeloadiszerotoeliminateelasticeffects.CreepRuptureStrengthStressrequiredtocausefractureinacreeptestwithinas

20、pecifiedtime.AlternatetermisStressRuptureStrength.CreepStrengthMaximumStressrequiredtocauseaspecifiedamountofcreepinaspecifiedtime.AlsousedtodescribemaximumStressthatcanbegeneratedinamaterialatconstanttemperatureunderwhichcreepratedecreaseswithtime.Analternatetermiscreeplimit.CreepTestMethodfordeter

21、miningcreeporstressrelaxationbehavior.Todeterminecreepproperties,materialissubjectedtoprolongedconstanttensionorcompressionloadingatconstanttemperature.Deformationisrecordedatspecifiedtimeintervalsandacreepvs.timediagramisplotted.Slopeofcurveatanypointiscreeprate.Iffailureoccurs,itterminatestestandT

22、imeforRuptureisrecorded.Ifspecimendoesnotfracturewithintestperiod,creeprecoverymaybemeasured.Todeterminestressrelaxationofmaterial,specimenisdeformedagivenamountanddecreaseinstressoverprolongedperiodofexposureatconstanttemperatureisrecorded.StandardcreeptestingproceduresaredetailedinASTME-139,ASTMD-

23、2990andD-2991(plastics)andASTMD-2294(adhesives).CrushResistanceLoadrequiredtoproducefractureinaglassspheresubjectedtocrushloading.(ASTMD-1213).CrushingLoadMaximumcompressiveforceappliedduringacompressionorcrushingtest.Formaterialsthatdonotshatter,crushingloadisdefinedastheforcerequiredtoproduceaspec

24、ifiedtypeoffailure.CrushingStrengthCompressiveloadrequiredtocauseacracktoforminasinteredmetalpowderbearing(ASTMB-438andB-439).ColdcrushingstrengthofrefractorybricksandshapesisthegrosscompressiveStressrequiredtocausefracture.(ASTMC-133).CompoundingThecombinationofpolymerswithothermaterialseitherbymea

25、nsofmechanical(dry)blendingormeltstateblendingCrossheadThisisthemainbeamonthetestingmachine.Itisthisbeamthatmoveseitherupordownproducingacompressiveortensileforce.Agripisattachedtothecrossheadandthetestpieceisattachedtothegrip.Thedistancethatthecrossheadmovesthroughismeasuredfromarotatingopticalsens

26、or.CrossheadLoomAribboncablethatconnectsthemovingcrossheadtothemachineelectronics,tosupplytheloadcellwithavoltageandsupplythemachinewithaloadsignal.DDeformationEnergyEnergyrequiredtodeformamaterialaspecifiedamount.ItistheareaundertheStress-StrainDiagramuptoaspecifiedstrain.DeformationUnderLoadMeasur

27、eoftheabilityofrigidplasticstowithstandpermanentdeformationandtheabilityofnonrigidplasticstoreturntooriginalshapeafterdeformation.StandardtestmethodsfordeterminingbothtypesofdeformationunderloadaregiveninASTMD-621.Forrigidplastics,deformationisre-portedas%changeinheightofspecimenafter24hoursunderasp

28、ecifiedload.Fornonrigidplastics,resultsarereportedas%changeinheightafter3hoursunderloadandRecoveryinthe1-1/2hourperiodfollowingremovaloftheload.Recoveryis%increaseinheightcalculatedonbasisoforiginalheight.DelaminationStrengthMeasureofthenode-to-nodeBondStrengthofhoneycombcorematerials.Itisequaltothe

29、tensileloadappliedtoahoneycombpanelatfracturedividedbyitswidthtimesitsthickness.(ASTMC-363)DenierTheunitoflineardensityequaltothemassingramsper9000moffiber,yarn,orothertextilestrand.DryStrengthStrengthofanadhesivejointdeterminedimmediatelyafterdryingorafteraperiodofconditioninginaspecifiedatmosphere

30、.(ASTMD-2475)DuctilityExtenttowhichamaterialcansustainplasticdeformationwithoutrupture.ElongationandReductionofAreaarecommonindicesofductility.DynamicCreepCreepthatoccursunderfluctuatingloadortemperature.DieswellWheneverapolymermeltemergesfromadiethediameterorthicknessisalwayslargerthanthediameter(o

31、rgap)ofthedie.Atusualproductionthroughputs,diameterorthicknessratiosrangefrom1.20-1.40forPVCto1.50-2.00forcommercialgradePolyethyene'sandmuchmoreforsomepolymerscontainingahighmolecularweighttail.Itisanindicationoftheelasticityofthepolymer.Themoreelasticpolymersgivelargerswell.Ofcourse,bypullingt

32、heextrudatestheswellisreducedandofcourseextrudatescanbedrawndowntodiameters(orthickness)muchsmallerthanthediediameterorgap.DiameterUsedwherethecrosssectionshapeofthetestpieceisround.EEASL(Elongationataspecifiedload)EccentricityofLoading-Distancebetweentheactuallineofactionofcompressiveortensileloads

33、andthelineofactionthatwouldproduceauniformStressoverthecrosssectionofthespecimen.EdgeTearingStrengthMeasureoftheresistanceofpapertotearingwhenfoldedoveraV-notchbeamandloadedinatensiletestingmachine.Resultsarere-portedinlborkg.(SeeTearResistance)ElasticHysteresisDifferencebetweenstrainenergyrequiredt

34、ogenerateagivenStressinamaterialandelasticenergyatthatStress.Itistheenergydissipatedasheatinamaterialinonecycleofdynamictesting.Elastichysteresisdividedbyelasticdeformationenergyisequaltodampingcapacity.ElasticLimitGreatestStressthatcanbeappliedtoamaterialwithoutcausingpermanentdeformation.Formetals

35、andothermaterialsthathaveasignificantstraightlineportionintheirStress/straindiagram,elasticlimitisapproximatelyequaltoproportionallimit.Formaterialsthatdonotexhibitasignificantproportionallimit,elasticlimitisanarbitraryapproximation(theapparentelasticlimit).ElasticLimit,ApparentArbitraryapproximatio

36、noftheelasticlimitofmaterialsthatdonothaveasignificantstraightlineportiononaStress/straindiagram.ItisequaltotheStressatwhichtherateofstrainis50%greaterthanatzeroStress.ItistheStressatthepointoftangencybetweentheStress-ElasticHysteresisstraincurveandthelinehavingaslope,withrespecttotheStressaxis,50%g

37、reaterthantheslopeofthecurveattheorigin.ElasticityAbilityofamaterialtoreturntoitsoriginalshapewhenloadcausingdeformationisremoved.ElongationMeasureoftheductilityofamaterialdeterminedinaTensileTest.Itistheincreaseingagelength(measuredafterrupture)dividedbyoriginalgagelength.Higherelongationindicatesh

38、igherductility.Elongationcannotbeusedtopredictbehaviorofmaterialssubjectedtosuddenorrepeatedloading.EmbrittlementReductioninductilityduetophysicalorchemicalchanges.EnduranceAlternatetermforFatigueLimit.EngineeringStressLoadappliedtoaspecimeninatensionorcompressiontestdividedbythecross-sectionalareao

39、fthespecimen.Thechangeincross-sectionalareathatoccurswithincreasesanddecreasesinappliedload,isdisregardedincomputingengineeringStress.ItisalsocalledconventionalStress.ExtensometerInstrumentformeasuringchangesinlineardimensions.AlsocalledaStraingauge.FrequentlybasedonStraingaugetechnology.EyeEndAnada

40、pterthatfitstoaloadcellormachine,thatenablesgriporjigstobeattachedFFatiguePermanentstructuralchangethatoccursinamaterialsubjectedtofluctuatingStressandstrain.However,inthecaseofglass,fatigueisdeterminedbylong-termstatictestingandisanalogoustoStressruptureinothermaterials.Ingeneral,fatiguefailurecano

41、ccurwithStresslevelsbelowtheelasticlimit.FatigueLifeNumberofcyclesoffluctuatingStressandstrainofaspecifiednaturethatamaterialwillsustainbeforefailureoccurs.FatiguelifeisafunctionofthemagnitudeofthefluctuatingStress,geometryofthespecimenandtestconditions.AnS-Ndiagramisaplotofthefatiguelifeatvariousle

42、velsoffluctuatingStress.FatigueLimitMaximumfluctuatingStressamaterialcanendureforaninfinitenumberofcycles.ItisusuallydeterminedfromanS-NdiagramandisequaltotheStresscorrespondingtotheasymptoteofthelocusofpointscorrespondingtothefatiguelifeofanumberoffatiguetestspecimens.Analternatetermisendurancelimi

43、t.FatigueNotchFactorRatiooffatiguestrengthofaspecimenwithnostressconcentrationtofatiguestrengthofaspecimenwithanotchorotherstressraisers.FatiguenotchfactorisusuallylowerthanthetheoreticalStressConcentrationFactorbecauseofstressreliefduetoplasticdeformation.Analternatetermisstrengthreductionratio.Fat

44、igueRatioRatiooffatiguestrengthorfatiguelimittotensilestrength.Formanymaterials,fatigueratiomaybeusedtoestimatefatiguepropertiesfromdataobtainedintensiontests.FatigueStrengthMagnitudeoffluctuatingStressrequiredtocausefailureinafatiguetestspecimenafteraspecifiednumberofcyclesofloading.Usuallydetermin

45、eddirectlyfromtheS-Ndiagram.FatigueStrengthReductionFactorAnalternatetermforfatiguenotchfactor.FatigueTestAmethodfordeterminingthebehaviorofmaterialsunderfluctuatingloads.Aspecifiedmeanload(whichmaybezero)andanalternatingloadareappliedtoaspecimenandthenumberofcyclesrequiredtoproducefailure(fatigueli

46、fe)isrecorded.FiberStressStressthroughapointinapartinwhichStressdistributionisnotuniform.FlexResistanceAbilityofmaterialtosustainrepeatedcompressiveloadswithoutdamage.FlexuralModulusofElasticityAlternatetermforModulusinBending.FlexuralStrengthMaximumfiberstressdevelopedinaspecimenjustbeforeitcrackso

47、rbreaksinaflexuretest.FlexuralYieldStrengthisreportedinsteadofflexuralstrengthformaterialsthatdonotcrackintheflexuretest.Analternatetermismodulusofrupture.FlexureTestMethodformeasuringbehaviorofmaterialssubjectedtosimplebeamloading.Specimenissupportedontwoknifeedgesasasimplebeamandloadisappliedatits

48、midpoint.Maximumfiberstressandmaximumstrainarecalculatedforincrementsofload.Resultsareplottedinastress-straindiagram,andmaximumfiberstressatfailureisflexuralstrength.FlexuralYieldStrengthisreportedformaterialsthatdonotcrack.FlowStressStressrequiredtocausePlasticDeformation.FractureStressTrueStressge

49、neratedinamaterialatfracture.FractureTestVisualtestwhereaspecimenisfracturedandexaminedforgrainsize,casedepth,etc.FractureToughnessAbilityofamaterialtoresistcrackpropagationwhensubjectedtoshockloadasinanImpactTest.FractionalmeltindexAmeltflowindexoflessthan1.0FlexuralTypicallyacompressiveortensilefo

50、rcedesignedtobendasamplethatissupportedateitherend。GGlasstransition(Tg)Thelowesttemperature,atwhichapolymercanbeconsiderdsoftenedandpossiblyflowableforHDPEandLDPEitis-100CandforPS+100c.GaugeLengthThegaugelengthduringatensiletestisthelengthofpartofthecylindrical/prismaticportionofthespecimenidentifie

51、dbytwogaugemarks.GaugeLengthistheoriginallengthofthatportionofthetestpieceoverwhichstrainorchangeoflengthisdetermined.Thegaugelengthisnormallylessthanthefulltestpiecelengthandisessentiallyuserdefined.HHardnessMeasureofamaterial'sresistancetolocalizedPlasticDeformation.Mosthardnesstestsinvolveind

52、entation,buthardnessmaybereportedasresistancetoscratching(filetest),orreboundofaprojectilebouncedoffthematerial(scleroscopehardness).SomecommonmeasuresofindentationhardnessareBrinellHardnessNumber,RockwellHardnessNumber,ASTMHardnessNumber,DiamondPyramidImpactTestHardnessNumber,DurometerHardness,Knoo

53、pHardness,andPfundHardness.AtablerelatingvarioustypesofhardnessvaluesofmetalsisgiveninASTME-140.Hardnessoftenisagoodindicationoftensileandwearpropertiesofamaterial.Hooke'sLawStressisdirectlyproportionaltoStrain.Hooke'slawassumesperfectlyelasticbehavior.Itdoesnottakeintoaccountplasticordynami

54、clossproperties.Highloadmeltflowindex(Hlmfi)Meltflowindexusingahigherthantheusual(2.16kg)weight.ForPE,itisusually10kg.ImpactEnergyEnergyrequiredtofractureapartsubjectedtoshockloadingasinanImpactTest.Alternatetermsareimpactvalue,impactstrength,impactresistance,andenergyabsorption.ImpactStrengthEnergy

55、requiredtofractureaspecimensubjectedtoshockloading,asinanimpacttest.Alternatetermsareimpactenergy,impactvalue,impactresistanceandenergyabsorption.ItisanindicationoftheToughnessofthematerial.ImpactTestAmethodfordeterminingbehaviorofmaterialsubjectedtoshockloadinginbending,tension,ortorsion.Thequantit

56、yusuallymeasuredistheenergyabsorbedinbreakingthespecimeninasingleblow,asintheCharpyImpactTest,IzodImpactTest,andTensionImpactTest.Impacttestsalsoareperformedbysubjectingspecimenstomultipleblowsofincreasingintensity,asinthedropballimpacttest,andrepeatedblowimpacttest.Impactresilienceandscleroscopehar

57、dnessaredeterminedinnondestructiveimpacttests.KKinkTestMethodfordeterminingductilityofmetalwire.K-ValueofPVCAmeasureofthemolecularweightofPVCbasedonmeasurementsofviscosityofaPVCsolution.Itrangesusuallybetween35and80.LowK-Valueimplylowmolecularweight(whichiseassytoprocessbuthasinferiorproperties)andh

58、ighK-Valueimplyhighmolecularweight,(whichisdifficulttoprocess,buthasoutstandingproperties)LLASELoadAtSpecifiedElongation.LinearDensityMassperunitlength.LoadProtectSeeSpecimenProtectLoad-DeflectionDiagramPlotofloadversuscorrespondingdeflection.LeadscrewUsedtotransferthemotordrivetothecrossheadLimitSwitchesMagneticorelectricallyoperatedswitchesfittedtotheverticalcolumnofamachinethatdisablesthedrivesystemofamachinewhenthecrossheadmovementactivatesthem.Theswitchesareuserdefinedandpreventdamagetotestspecimens,loadcellsandgripsduetooperatorerror。LoadCalibrationApro