ASTM_C_1291_-_16.pdf

Designation:C129116Standard Test Method forElevated Temperature Tensile Creep Strain,Creep StrainRate,and Creep Time-to-Failure for Monolithic AdvancedCeramics1This standard is issued under the fixed designation C1291;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 tensilecreep strain,creep strain rate,and creep time-to-failure foradvanced monolithic ceramics at elevated temperatures,typi-cally between 1073 and 2073 K.A variety of test specimengeometries are included.The creep strain at a fixed temperatureis evaluated from direct measurements of the gage lengthextension over the time of the test.The minimum creep strainrate,which may be invariant with time,is evaluated as afunction of temperature and applied stress.Creep time-to-failure is also included in this test method.1.2 This test method is for use with advanced ceramics thatbehave as macroscopically isotropic,homogeneous,continu-ous materials.While this test method is intended for use onmonolithic ceramics,whisker-or particle-reinforced compositeceramics as well as low-volume-fraction discontinuous fiber-reinforced composite ceramics may also meet these macro-scopic behavior assumptions.Continuous fiber-reinforced ce-ramic composites(CFCCs)do not behave as macroscopicallyisotropic,homogeneous,continuous materials,and applicationof this test method to these materials is not recommended.1.3 The values in SI units are to be regarded as the standard(see IEEE/ASTM SI 10).The values given in parentheses aremathematical conversions to inch-pound units that are pro-vided for information only and are not considered standard.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C1145 Terminology of Advanced CeramicsC1273 Test Method for Tensile Strength of MonolithicAdvanced Ceramics at Ambient TemperaturesE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE139 Test Methods for Conducting Creep,Creep-Rupture,and Stress-Rupture Tests of Metallic MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE220 Test Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF)Tables for Standardized ThermocouplesE639 Test Method for Measuring Total-Radiance Tempera-ture of Heated Surfaces Using a Radiation Pyrometer(Withdrawn 2011)3E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1012 Practice for Verification of Testing Frame and Speci-men Alignment Under Tensile and Compressive AxialForce ApplicationIEEE/ASTM SI 10 American National Standard for Use ofthe International System of Units(SI):The Modern MetricSystem3.Terminology3.1 DefinitionsThe definitions of terms relating to creeptesting,which appear in Section E of Terminology E6 shall1This 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 Sept.1,2016.Published October 2016.Originallyapproved in 1995.Last previous edition approved in 2010 as C1291 00a(2010).DOI:10.1520/C1291-16.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 apply to the terms used in this test method.For the purpose ofthis test method only,some of the more general terms are usedwith the restricted meanings given as follows.3.2 Definitions of Terms Specific to This Standard:3.2.1 axial strain,a,L/L,naverage of the strain mea-sured on diametrically opposed sides and equally distant fromthe test specimen axis.3.2.2 bending strain,bL/L,ndifference between thestrain at the surface and the axial strain.3.2.2.1 DiscussionIn general,it varies from point to pointaround and along the gage length of the test specimen.E10123.2.3 creep-rupture test,ntest in which progressive testspecimen deformation and the time-to-failure are measured.Ingeneral,deformation is greater than that developed during acreep test.3.2.4cree