【英文标准名称】:StandardTestMethodsforDeterminationofFractureToughnessofAdvancedCeramicsatAmbientTemperature
【原文标准名称】:室温下高级陶瓷断裂韧性测定的标准试验方法
【标准号】:ASTMC1421-2009
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【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】:
【英文主题词】:advancedceramics;chevronnotch;fracturetoughness;precrackedbeam;surfacecrackinflexure;Advancedceramics;Ambienttemperature;Chevronnotchedspecimen;Cracking--ceramics;Flexuraltesting--ceramics;Fracturetesting--advancedceramics;Precrac
【摘要】:Fracturetoughness,KIc,isameasureoftheresistancetocrackextensioninabrittlematerial.Thesetestmethodsmaybeusedformaterialdevelopment,materialcomparison,qualityassessment,andcharacterization.Thepbandthevbfracturetoughnessvaluesprovideinformationonthefractureresistanceofadvancedceramicscontaininglargesharpcracks,whilethescfracturetoughnessvalueprovidesthisinformationforsmallcrackscomparableinsizetonaturalfracturesources.Cracksofdifferentsizesmaybeusedforthescmethod.IfthefracturetoughnessvaluesvaryasafunctionofthecracksizeitcanbeexpectedthatKIscwilldifferfromKIpbandKIvb.1.1Thesetestmethodscoverthefracturetoughness,KIc,determinationofadvancedceramicsatambienttemperature.ThemethodsdetermineKIpb(precrackedbeamtestspecimen),KIsc(surfacecrackinflexure),andKIvb(chevron-notchedbeamtestspecimen).Thefracturetoughnessvaluesaredeterminedusingbeamtestspecimenswithasharpcrack.Thecrackiseitherastraight-throughcrackformedviabridgeflexure(pb),orasemi-ellipticalsurfacecrackformedviaKnoopindentation(sc),oritisformedandpropagatedinachevronnotch(vb),asshowninFig.1.Note18212;Thetermsbend(ing)andflexurearesynonymousinthesetestmethods.1.2ThesetestmethodsareapplicabletomaterialswitheitherflatorwithrisingR-curves.Differencesintestprocedureandanalysismaycausethevaluesfromeachtestmethodtobedifferent.Formanymaterials,suchasthesiliconnitrideStandardReferenceMaterial2100,thethreemethodsgiveidenticalresultsatroomtemperatureinambientair.1.3Thefracturetoughnessvaluesforamaterialcanbefunctionsofenvironment,testrateandtemperature.Thesetestmethodsgivefracturetoughnessvaluesforspecificconditionsofenvironment,testrateandtemperature.1.4Thesetestmethodsareintendedprimarilyforusewithadvancedceramicswhicharemacroscopicallyhomogeneous.Certainwhisker-orparticle-reinforcedceramicsmayalsomeetthemacroscopicbehaviorassumptions.Singlecrystalsmayalsobetested.1.5Thisstandardbeginswithamainbodythatprovidesinformationonfracturetoughnesstestingingeneral.Itisfollowedbyannexesandappendiceswithspecificinformationfortheparticulartestmethods.MainBody
Section
Scope
1
ReferencedDocuments
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Terminology(includingdefinitions,orientationandsymbols)
3
SummaryofTestMethods
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SignificanceandUse
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Interferences
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Apparatus
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TestSpecimenConfigurations,DimensionsandPreparations
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GeneralProcedures
MIL-T-12020C, MILITARY SPECIFICATION: TRIPOD, PHOTOGRAPHIC LM-41() (21 NOV 1984) [NO S/S DOCUMENT]., This specification covers the requirement for one type of medium duty tripod with pan and tilt head, and carrying case, designated as Tripod, Photographic LM-41() (See 6.4).