ASTM C1327-2008 高级陶瓷的维氏压痕硬度的标准试验方法

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【英文标准名称】:StandardTestMethodforVickersIndentationHardnessofAdvancedCeramics
【原文标准名称】:高级陶瓷的维氏压痕硬度的标准试验方法
【标准号】:ASTMC1327-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【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;cracks;indentation;microscope;Vickershardness;Advancedceramics;Hardness(indentation);Microscopicexamination--advancedceramics;Opticalmicroscopy;Vickershardness(HV)
【摘要】:Foradvancedceramics,Vickersindentersareusedtocreateindentationswhosesurface-projecteddiagonalsaremeasuredwithopticalmicroscopes.TheVickersindentercreatesasquareimpressionfromwhichtwosurface-projecteddiagonallengthsaremeasured.Vickershardnessiscalculatedfromtheratiooftheappliedloadtotheareaofcontactofthefourfacesoftheundeformedindenter.(Incontrast,Knoopindentersarealsousedtomeasurehardness,butKnoophardnessiscalculatedfromtheratiooftheappliedloadtotheprojectedareaonthespecimensurface.)Vickersindentationhardnessisoneofmanypropertiesthatisusedtocharacterizeadvancedceramics.AttemptshavebeenmadetorelateVickersindentationhardnesstootherhardnessscales,butnogenerallyacceptedmethodsareavailable.Suchconversionsarelimitedinscopeandshouldbeusedwithcaution,exceptforspecialcaseswhereareliablebasisfortheconversionhasbeenobtainedbycomparisontests.Vickersindentationdiagonallengthsareapproximately2.8timesshorterthanthelongdiagonalofKnoopindentations,andtheindentationdepthisapproximately1.5timesdeeperthanKnoopindentationsmadeatthesameforce.Vickersindentationsareinfluencedlessbyspecimensurfaceflatness,parallelism,andsurfacefinishthanKnoopindentations,buttheseparametersmustbeconsiderednonetheless.VickersindentationsaremuchmorelikelytocausecracksinadvancedceramicsthanKnoopindentations.Thecracksmayinfluencethemeasuredhardnessbyfundamentallyalteringthedeformationprocessesthatcontributetotheformationofanimpression,andtheymayimpairorprecludemeasurementofthediagonallengthsduetoexcessivedamageattheindentationtipsorsides.Afullhardnesscharacterizationincludesmeasurementsoverabroadrangeofindentationforces.Vickershardnessofceramicsusuallydecreaseswithincreasingindentationsizeorindentationforce.Thetrendisknownastheindentationsizeeffect(ISE).Hardnessapproachesaplateauconstanthardnessatsufficientlylargeindentationsizeorforces.Thetestforcesorloadsthatareneededtoachieveaconstanthardnessvarywiththeceramic.Thetestforcespecifiedinthisstandardisintendedtobesufficientlylargethathardnessiseitherclosetoorontheplateau,butnotsolargeastointroduceexcessivecracking.AcomprehensivecharacterizationoftheISEisrecommendedbutisbeyondthescopeofthistestmethod,whichmeasureshardnessatasingle,designatedforce.1.1ThistestmethodcoversthedeterminationoftheVickersindentationhardnessofadvancedceramics.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:Q32
【国际标准分类号】:81_060_99
【页数】:8P.;A4
【正文语种】:英语