ASTM_C_1161_-_13.pdf

Designation:C116113Standard Test Method forFlexural Strength of Advanced Ceramics at AmbientTemperature1This standard is issued under the fixed designation C1161;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the determination of flexuralstrength of advanced ceramic materials at ambient temperature.Four-point14point and three-point loadings with prescribedspans are the standard as shown in Fig.1.Rectangularspecimens of prescribed cross-section sizes are used withspecified features in prescribed specimen-fixture combinations.Test specimens may be 3 by 4 by 45 to 50 mm in size that aretested on 40 mm outer span four-point or three-point fixtures.Alternatively,test specimens and fixture spans half or twicethese sizes may be used.The method permits testing ofmachined or as-fired test specimens.Several options formachining preparation are included:application matchedmachining,customary procedure,or a specified standard pro-cedure.This method describes the apparatus,specimenrequirements,test procedure,calculations,and reporting re-quirements.The test method is applicable to monolithic orparticulate-or whisker-reinforced ceramics.It may also beused for glasses.It is not applicable to continuous fiber-reinforced ceramic composites.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E4 Practices for Force Verification of Testing MachinesC1239 Practice for Reporting Uniaxial Strength Data andEstimating Weibull Distribution Parameters for AdvancedCeramicsC1322 Practice for Fractography and Characterization ofFracture Origins in Advanced CeramicsC1368 Test Method for Determination of Slow CrackGrowth Parameters of Advanced Ceramics by ConstantStress-Rate Strength Testing at Ambient TemperatureE337 Test Method for Measuring Humidity with a Psy-chrometer(the Measurement of Wet-and Dry-Bulb Tem-peratures)2.2 Military Standard:MIL-STD-1942(MR)Flexural Strength of High Perfor-mance Ceramics at Ambient Temperature33.Terminology3.1 Definitions:3.1.1 complete gage section,nthe portion of the specimenbetween the two outer bearings in four-point flexure andthree-point flexure fixtures.NOTE1In this standard,the complete four-point flexure gage sectionis twice the size of the inner gage section.Weibull statistical analysis onlyincludes portions of the specimen volume or surface which experiencetensile stresses.3.1.2 flexural strengtha measure of the ultimate strengthof a specified beam in bending.3.1.3 four-point14point flexureconfiguration of flexuralstrength testing where a specimen is symmetrically loaded attwo locations that are situated one quarter of the overall span,away from the outer two support bearings(see Fig.1).3.1.4 Fully-articulating fixture,na flexure fixture de-signed to be used either with flat and parallel specimens or withuneven or nonparallel specimens.The fixture allows fullindependent articulation,or pivoting,of all rollers about thespecimen long axis to match the specimen surface.In addition,the upper or lower pairs are free to pivot to distribute forceevenly to the bearing cylinders on either side.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 Aug.1,2013.Published September 2013.Originallyapproved in 1990.Last previous edition approved in 2008 as C1161 02c(2008)1.DOI:10.1520/C1161-13.2For 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 Standardization Documents Order Desk,DODSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,http:/www.dodssp.daps.mil.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE2See Annex A1 for schematic illustrations of the requiredpivoting movements.NOTE3A three-point fixture has the inner pair of bearing cylindersreplaced by a single bearing cylinder.3.1.5 inert flexural strength,na measure of the strength ofspecified beam in bending as determined in an appropriate inertcondition whereby no slow crack growth oc