ASTM C1421-2001b(2007) 测定室温下高级陶瓷断裂韧性的标准试验方法

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【英文标准名称】:StandardTestMethodsforDeterminationofFractureToughnessofAdvancedCeramicsatAmbientTemperature
【原文标准名称】:测定室温下高级陶瓷断裂韧性的标准试验方法
【标准号】:ASTMC1421-2001b(2007)
【标准状态】:现行
【国别】:
【发布日期】:2001
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:C28.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:测定;陶瓷;高级工业陶瓷;断裂韧性;试验方法;环境温度
【英文主题词】:advancedceramics;chevronnotch;fracturetoughness;precrackedbeam;surfacecrackinflexure
【摘要】:Thesetestmethodsmaybeusedformaterialdevelopment,materialcomparison,qualityassessment,andcharacterization.Thepbandthevbfracturetoughnessvaluesprovideinformationonthefractureresistanceofadvancedceramicscontaininglargesharpcracks,whilethescfracturetoughnessvalueprovidesthisinformationforsmallcrackscomparableinsizetonaturalfracturesources.Note48212;Cracksofdifferentsizesmaybeusedforthescmethod.IfthefracturetoughnessvaluesvaryasafunctionofthesurfacecracksizeitcanbeexpectedthatKIscwilldifferfromKIpbandKIvb.1.1ThesetestmethodscoverthefracturetoughnessdeterminationofKIpb(precrackedbeamtestspecimen),KIsc(surfacecrackinflexure),andKIvb(chevron-notchedbeamtestspecimen)ofadvancedceramicsatambienttemperature.Thefracturetoughnessvaluesaredeterminedusingbeamtestspecimenswithasharpcrack.Thecrackiseitherastraight-throughcrack(pb),orasemi-ellipticalsurfacecrack(sc),oritispropagatedinachevronnotch(vb).Note1Thetermsbend(ing)andflexurearesynonymousinthesetestmethods.1.2Thesetestmethodsdeterminefracturetoughnessvaluesbasedonaforceandcracklengthmeasurement(pb,sc),oraforcemeasurementandaninferredcracklength(vb).Ingeneral,thefracturetoughnessisdeterminedfrommaximumforce.Appliedforceanddisplacementoranalternative(forexample,time)arerecordedforthepbtestspecimenandvbtestspecimen.1.3ThesetestmethodsareapplicabletomaterialswitheitherflatorwithrisingR-curves.Thefracturetoughnessmeasuredfromstablecrackextensionmaybedifferentthanthatmeasuredfromunstablecrackextension.ThisdifferencemaybemorepronouncedformaterialsexhibitingarisingR-curve.Note2OnedifferencebetweentheproceduresinthesetestmethodsandtestmethodssuchasTestMethodE399,whichmeasurefracturetoughness,KIc,byonesetofspecificoperationalprocedures,isthatTestMethodE399focusesonthestartofcrackextensionfromafatigueprecrackformetallicmaterials.Inthesetestmethodsthetestmethodsforadvancedceramicsmakeuseofeitherasharpprecrackformedviabridgeflexure(pb)orviaKnoopindent(sc)priortothetest,oracrackformedduringthetest(vb).Differencesintestprocedureandanalysismaycausethevaluesfromeachtestmethodtobedifferent.Therefore,fracturetoughnessvaluesdeterminedwiththesemethodscannotbeinterchangedwithKIcasdefinedinTestMethodE399andmaynotbeinterchangeablewitheachother.1.4Thesetestmethodsgivefracturetoughnessvalues,KIpb,KIsc,andKIvb,forspecificconditionsofenvironment,testrateandtemperature.Thefracturetoughnessvalues,KIpb,KIsc,andKIvbforamaterialcanbefunctionsofenvironment,testrateandtemperature.1.5Thesetestmethodsareintendedprimarilyforusewithadvancedceramicswhicharemacroscopicallyhomogeneous.Certainwhisker-orparticle-reinforcedceramicsmayalsomeetthemacroscopicbehaviorassumptions.1.6Thesetestmethodsaredividedintothreemajorpartsandrelatedsubpartsasshownbelow.Thefirstmajorpartisthemainbodyandprovidesgeneralinformationonthetestmethodsdescribed,theapplicabilitytomaterialscomparisonandqualification,andrequirementsandrecommendationsforfracturetoughnesstesting.Thesecondmajorpartiscomposedofannexesthatprovideprocedures,testspecimendesign,precracking,testing,anddataanalysisforeachmethod.AnnexA1describessuggestedtestfixtures,......
【中国标准分类号】:Q32
【国际标准分类号】:81_060_30
【页数】:34P.;A4
【正文语种】: