Designation:C1326−13(Reapproved2018)StandardTestMethodforKnoopIndentationHardnessofAdvancedCeramics1ThisstandardisissuedunderthefixeddesignationC1326;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThistestmethodcoversthedeterminationoftheKnoopindentationhardnessofadvancedceramics.Inthistest,apointed,rhombic-based,pyramidaldiamondindenterofpre-scribedshapeispressedintothesurfaceofaceramicwithapredeterminedforcetoproducearelativelysmall,permanentindentation.Thesurfaceprojectionofthelongdiagonalofthepermanentindentationismeasuredusingalightmicroscope.ThelengthofthelongdiagonalandtheappliedforceareusedtocalculatetheKnoophardnesswhichrepresentsthematerial’sresistancetopenetrationbytheKnoopindenter.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Units—WhenKnoopandVickershardnesstestsweredeveloped,theforcelevelswerespecifiedinunitsofgrams-force(gf)andkilograms-force(kgf).ThisstandardspecifiestheunitsofforceandlengthintheInternationalSystemofUnits(SI);thatis,forceinnewtons(N)andlengthinmmorµm.However,becauseofthehistoricalprecedentandcontin-uedcommonusage,forcevaluesingfandkgfunitsareoccasionallyprovidedforinformation.Thistestmethodspeci-fiesthatKnoophardnessbereportedeitherinunitsofGPaorasadimensionlessKnoophardnessnumber.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbyt...
