作者:标准资料网 时间:2024-05-19 04:06:05   浏览:8407   来源:标准资料网

【英文标准名称】:StandardTestMethodforElevatedTemperatureTensileCreepStrain,CreepStrainRate,andCreepTime-to-FailureforAdvancedMonolithicCeramics
【原文标准名称】:高级单片陶瓷的高温抗拉蠕变应变,蠕变应变率及蠕变断裂时间的标准试验方法
【标准号】:ASTMC1291-2000a(2010)
【标准状态】:现行
【国别】:
【发布日期】:2000
【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】:高级陶瓷;蠕变;整体式陶瓷;拉伸
【英文主题词】:advancedceramics;creep;monolithicceramics;tensile
【摘要】:Creeptestsmeasurethetime-dependentdeformationunderloadatagiventemperature,and,byimplication,theload-carryingcapabilityofthematerialforlimiteddeformations.Creep-rupturetests,properlyinterpreted,provideameasureoftheload-carryingcapabilityofthematerialasafunctionoftimeandtemperature.Thetwotestscomplimenteachotherindefiningtheload-carryingcapabilityofamaterialforagivenperiodoftime.Inselectingmaterialsanddesigningpartsforserviceatelevatedtemperatures,thetypeoftestdatausedwilldependonthecriteriaforload-carryingcapabilitythatbestdefinestheserviceusefulnessofthematerial.Thistestmethodmaybeusedformaterialdevelopment,qualityassurance,characterization,anddesigndatageneration.High-strength,monolithicceramicmaterials,generallycharacterizedbysmallgrainsizes(x003C;50x03BC;m)andbulkdensitiesneartheirtheoreticaldensity,arecandidatesforload-bearingstructuralapplicationsatelevatedtemperatures.Theseapplicationsinvolvecomponentssuchasturbinebladeswhicharesubjectedtostressgradientsandmultiaxialstresses.Dataobtainedfordesignandpredictivepurposesshouldbeobtainedusinganyappropriatecombinationoftestmethodsthatprovidethemostrelevantinformationfortheapplicationsbeingconsidered.Itisnotedherethatceramicmaterialstendtocreepmorerapidlyintensionthanincompression(1,2,3).Thisdifferenceresultsintime-dependentchangesinthestressdistributionandthepositionoftheneutralaxiswhentestsareconductedinflexure.Asaconsequence,deconvolutionofflexuralcreepdatatoobtaintheconstitutiveequationsneededfordesigncannotbeachievedwithoutsomedegreeofuncertaintyconcerningtheformofthecreepequations,andthemagnitudeofthecreeprateintensionvis-a-visthecreeprateincompression.Therefore,creepdatafordesignandlifepredictionshouldbeobtainedinbothtensionandcompression,aswellastheexpectedservicestressstate.1.1Thistestmethodcoversthedeterminationoftensilecreepstrain,creepstrainrate,andcreeptime-to-failureforadvancedmonolithicceramicsatelevatedtemperatures,typicallybetween1073and2073K.Avarietyofspecimengeometriesareincluded.Thecreepstrainatafixedtemperatureisevaluatedfromdirectmeasurementsofthegagelengthextensionoverthetimeofthetest.Theminimumcreepstrainrate,whichmaybeinvariantwithtime,isevaluatedasafunctionoftemperatureandappliedstress.Creeptime-to-failureisalsoincludedinthistestmethod.1.2Thistestmethodisforusewithadvancedceramicsthatbehaveasmacroscopicallyisotropic,homogeneous,continuousmaterials.Whilethistestmethodisintendedforuseonmonolithicceramics,whisker-orparticle-reinforcedcompositeceramicsaswellaslow-volume-fractiondiscontinuousfiber-reinforcedcompositeceramicsmayalsomeetthesemacroscopicbehaviorassumptions.Continuousfiber-reinforcedceramiccomposites(CFCCs)donotbehaveasmacroscopicallyisotropic,homogeneous,continuousmaterials,andapplicationofthistestmethodtothesematerialsisnotrecommended.1.3ThevaluesinSIunitsaretoberegardedasthestandard(see).1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:
【国际标准分类号】:81_060_99
【页数】:15P.;A4
【正文语种】: