ASTM_C_1326_-_13_2018.pdf

Designation:C132613(Reapproved 2018)Standard Test Method forKnoop Indentation Hardness of Advanced Ceramics1This standard is issued under the fixed designation C1326;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the Knoopindentation hardness of advanced ceramics.In this test,apointed,rhombic-based,pyramidal diamond indenter of pre-scribed shape is pressed into the surface of a ceramic with apredetermined force to produce a relatively small,permanentindentation.The surface projection of the long diagonal of thepermanent indentation is measured using a light microscope.The length of the long diagonal and the applied force are usedto calculate the Knoop hardness which represents the materialsresistance to penetration by the Knoop indenter.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 UnitsWhen Knoop and Vickers hardness tests weredeveloped,the force levels were specified in units of grams-force(gf)and kilograms-force(kgf).This standard specifiesthe units of force and length in the International System ofUnits(SI);that is,force in newtons(N)and length in mm orm.However,because of the historical precedent and contin-ued common usage,force values in gf and kgf units areoccasionally provided for information.This test method speci-fies that Knoop hardness be reported either in units of GPa oras a dimensionless Knoop hardness number.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2C730 Test Method for Knoop Indentation Hardness of GlassC849 Test Method for Knoop Indentation Hardness of Ce-ramic WhitewaresE4 Practices for Force Verification of Testing MachinesE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE384 Test Method for Microindentation Hardness of Mate-rialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units(SI)(The Modern Metric System)2.2 European Standard:3CEN ENV 843-4 Advanced Technical Ceramics,MonolithicCeramics,Mechanical Properties at Room Temperature,Part 4:Vickers,Knoop,and Rockwell Superficial Hard-ness Tests2.3 ISO Standard:4ISO 9385 Glass and Glass CeramicsKnoop Hardness Test3.Terminology3.1 Definitions:3.1.1 Knoop hardness number(HK),nan expression ofhardness obtained by dividing the force applied to the Knoopindenter by the projected area of the permanent impressionmade by the indenter.3.1.2 Knoop indenter,na rhombic-based pyramidal-shaped diamond indenter with edge angles of 172 30 and130 00.4.Summary of Test Method4.1 This test method describes an indentation hardness testusing a calibrated machine to force a pointed,rhombic-based,1This test method is under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and is the direct responsibility of Subcommittee C28.01 onMechanical Properties and Performance.Current edition approved Jan.1,2018.Published January 2018.Originallyapproved in 1996.Last previous edition approved in 2013 as C1326 13.DOI:10.1520/C1326-13R18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from European Committee for Standardization(CEN),36 rue deStassart,B-1050,Brussels,Belgium,http:/www.cenorm.be.4Available from International Organization for Standardization(ISO),1,ch.dela Voie-Creuse,Case postale 56,CH-1211,Geneva 20,Switzerland,http:/www.iso.ch.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 pyramidal diamond indenter having specified face angles,under a predetermined force,into the surface o