SAE AS5187 Fitting, Elbow, 45Md, Bulkhead, Hose
作者:标准资料网 时间:2024-05-12 06:43:25 浏览:9973
来源:标准资料网
Product Code:SAE AS5187
Title:Fitting, Elbow, 45Md, Bulkhead, Hose
Issuing Committee:G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Scope:No scope available.
【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
基本信息
| 标准名称： | ３０°渐开线花键用圆锥尾综合通端塞规 ｍ＝0.5~4Ｄ＝5~65 |
| 中标分类： |
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| 发布日期： | 1994-11-02 |
| 实施日期： | 1995-01-01 |
| 首发日期： | 1900-01-01 |
| 作废日期： | 1900-01-01 |
| 出版日期： | 1900-01-01 |
| 页数： | 71页 |
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