1、Designation: C1361 10Standard Practice forConstant-Amplitude, Axial, Tension-Tension Cyclic Fatigueof Advanced Ceramics at Ambient Temperatures1This standard is issued under the fixed designation C1361; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e 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. Scope*1.1 This practice covers the determination of constant-amplitude, axial tension-tension c
3、yclic fatigue behavior andperformance of advanced ceramics at ambient temperatures toestablish “baseline” cyclic fatigue performance. This practicebuilds on experience and existing standards in tensile testingadvanced ceramics at ambient temperatures and addressesvarious suggested test specimen geom
4、etries, test specimenfabrication methods, testing modes (force, displacement, orstrain control), testing rates and frequencies, allowable bend-ing, and procedures for data collection and reporting. Thispractice does not apply to axial cyclic fatigue tests of compo-nents or parts (that is, machine el
5、ements with non uniform ormultiaxial stress states).1.2 This practice applies primarily to advanced ceramicsthat macroscopically exhibit isotropic, homogeneous, continu-ous behaviour. While this practice applies primarily to mono-lithic advanced ceramics, certain whisker- or particle-reinforced comp
6、osite ceramics as well as certain discontinuousfibre-reinforced composite ceramics may also meet thesemacroscopic behaviour assumptions. Generally, continuousfibre-reinforced ceramic composites (CFCCs) do not macro-scopically exhibit isotropic, homogeneous, continuous behav-iour and application of t
7、his practice to these materials is notrecommended.1.3 The values stated in SI units are to be regarded as thestandard and are in accordance with IEEE/ASTM SI 10.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the us
8、er of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Refer to Section 7for specific precautions.2. Referenced Documents2.1 ASTM Standards:2C1145 Terminology of Advanced CeramicsC1273 Test Method for Tensile
9、 Strength of MonolithicAdvanced Ceramics at Ambient TemperaturesC1322 Practice for Fractography and Characterization ofFracture Origins in Advanced CeramicsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and
10、 Classification of Exten-someter SystemsE337 Test Method for Measuring Humidity with a Psy-chrometer (the Measurement of Wet- and Dry-Bulb Tem-peratures)E467 Practice for Verification of Constant Amplitude Dy-namic Forces in an Axial Fatigue Testing SystemE468 Practice for Presentation of Constant A
11、mplitude Fa-tigue Test Results for Metallic MaterialsE739 Practice for Statistical Analysis of Linear or Linear-ized Stress-Life ( S-N) and Strain-Life (e-N) Fatigue DataE1012 Practice for Verification of Test Frame and SpecimenAlignment Under Tensile and Compressive Axial ForceApplicationE1823 Term
12、inology Relating to Fatigue and Fracture Test-ingIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI) (The Modern Metric System)2.2 Military Handbook:1This practice is under the jurisdiction of ASTM Committee C28 on AdvancedCeramics and is the direct responsibility of Subcommitt
13、ee C28.01 on MechanicalProperties and Performance.Current edition approved July 15, 2010. Published August 2010. Originallyapproved in 1996. Last previous edition approved in 2007 as C1361 01 (2007).DOI: 10.1520/C1361-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
14、 ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
15、nshohocken, PA 19428-2959, United States.MIL-HDBK-790 Fractography and Characterization ofFracture Origins in Advanced Structural Ceramics33. Terminology3.1 DefinitionsDefinitions of terms relating to advancedceramics, cyclic fatigue, and tensile testing as they appear inTerminology C1145, Terminolo
16、gy E1823, and TerminologyE6, respectively, apply to the terms used in this practice.Selected terms with definitions non-specific to this practicefollow in 3.2 with the appropriate source given in parenthesis.Terms specific to this practice are defined in 3.3.3.2 Definitions of Terms Non Specific to
17、This Standard:3.2.1 advanced ceramic, na highly engineered, high per-formance predominately non-metallic, inorganic, ceramic ma-terial having specific functional attributes. (See TerminologyC1145.)3.2.2 axial strain LL1, nthe average longitudinalstrains measured at the surface on opposite sides of t
18、helongitudinal axis of symmetry of the test specimen by twostrain-sensing devices located at the mid length of the reducedsection. (See Practice E1012.)3.2.3 bending strain LL1, nthe difference between thestrain at the surface and the axial strain. In general, the bendingstrain varies from point to
19、point around and along the reducedsection of the test specimen. (See Practice E1012.)3.2.4 constant amplitude loading, nin cyclic fatigue load-ing, a loading in which all peak loads are equal and all of thevalley forces are equal. (See Terminology E1823.)3.2.5 cyclic fatigue, nthe process of progres
20、sive localizedpermanent structural change occurring in a material subjectedto conditions that produce fluctuating stresses and strains atsome point or points and that may culminate in cracks orcomplete fracture after a sufficient number of fluctuations. (SeeTerminology E1823.) See Fig. 1 for nomencl
21、ature relevant tocyclic fatigue testing.3.2.5.1 DiscussionIn glass technology static tests of con-siderable duration are called static fatigue tests, a type of testgenerally designated as stress-rupture.3.2.5.2 DiscussionFluctuations may occur both in loadand with time (frequency) as in the case of
22、random vibration.3.2.6 cyclic fatigue life, Nfthe number of loading cycles ofa specified character that a given test specimen sustains beforefailure of a specified nature occurs. (See Terminology E1823.)3.2.7 cyclic fatigue limit, Sf, FL2, nthe limiting value ofthe median cyclic fatigue strength as
23、the cyclic fatigue life, Nf,becomes very large. (for example, N106-107). (See Terminol-ogy E1823)3.2.7.1 DiscussionCertain materials and environmentspreclude the attainment of a cyclic fatigue limit. Valuestabulated as cyclic fatigue limits in the literature are frequently(but not always) values of
24、Sfat 50 % survival at Nfcycles ofstress in which the mean stress, Sm, equals zero.3.2.8 cyclic fatigue strength SN, FL2, nthe limitingvalue of the median cyclic fatigue strength at a particular cyclicfatigue life, Nf. (See Terminology E1823.)3.2.9 gage length, L, nthe original length of that portion
25、of the test specimen over which strain or change of length isdetermined. (See Terminology E6.)3.2.10 load ratio, nin cyclic fatigue loading, the algebraicratio of the two loading parameters of a cycle; the most widelyused ratios (see Terminology E1823):R 5minimum forcemaximum forceor R 5valley force
26、peak forceand:A5force amplitudemean forceor A5maximum force minimum force!maximum force 1 minimum force!3.2.11 modulus of elasticity FL2, nthe ratio of stress tocorresponding strain below the proportional limit. (See Termi-nology E6.)3.2.12 percent bending, nthe bending strain times 100divided by th
27、e axial strain. (See Practice E1012.)3.2.13 S-N diagram, na plot of stress versus the numberof cycles to failure. The stress can be maximum stress, Smax,minimum stress, Smin, stress range, DS or Sr, or stress ampli-tude, Sa. The diagram indicates the S-N relationship for aspecified value of Sm, A, R
28、 and a specified probability ofsurvival. For N, a log scale is almost always used, although alinear scale may also be used. For S, a linear scale is usuallyused, although a log scale may also be used. (See TerminologyE1823 and Practice E468.)3.2.14 slow crack growth, nsub-critical crack growth(exten
29、sion) that may result from, but is not restricted to, suchmechanisms as environmentally-assisted stress corrosion ordiffusive crack growth.3.2.15 tensile strength FL2, nthe maximum tensilestress which a material is capable of sustaining. Tensilestrength is calculated from the maximum force during a
30、tensiontest carried to rupture and the original cross-sectional area ofthe test specimen. (See Terminology E6.)3.3 Definitions of Terms Specific to This Standard:3.3.1 maximum stress, SmaxFL2, nthe maximum ap-plied stress during cyclic fatigue.3.3.2 mean stress, SmaxFL2, nthe average appliedstress d
31、uring cyclic fatigue such that3Available from Army Research Laboratory-Materials Directorate, AberdeenProving Ground, MD 21005.FIG. 1 Cyclic Fatigue Nomenclature and Wave FormsC1361 102Sm5Smax1 Smin2(1)3.3.3 minimum stress, SminFL2, nthe minimum appliedstress during cyclic fatigue.3.3.4 stress ampli
32、tude, SaFL2, nthe difference betweenthe mean stress and the maximum or minimum stress such thatSa5Smax Smin25 Smax Sm5 Sm Smin(2)3.3.5 stress range, DSorSrFL2, nthe difference be-tween the maximum stress and the minimum stress such thatDS = Sr= Smax Smin3.3.6 time to cyclic fatigue failure, tf t, nt
33、otal elapsedtime from test initiation to test termination required to reach thenumber of cycles to failure.4. Significance and Use4.1 This practice may be used for material development,material comparison, quality assurance, characterization, reli-ability assessment, and design data generation.4.2 H
34、igh-strength, monolithic advanced ceramic materialsare generally characterized by small grain sizes (50 Hz) that can cause internalheating (hysteresis) of the test specimen thereby affecting thecyclic fatigue life. If test specimen heating is likely to occur orwhen there is doubt, monitor the test s
35、pecimen temperatureduring the cycling. Possible methods are: the use of radiationthermometer, thermocouples adhered to the specimen, oroptical pyrometry.6.8.1 Environmental ConditionsFor ambient temperaturetests conducted under constant environmental conditions, con-trol temperature and relative hum
36、idity to within 63C and610 % RH, respectively. Measure and report temperature andrelative humidity in accordance with 9.3.5.7. Hazards7.1 During the conducting of this practice, the possibility offlying fragments of broken test material may be great. Thebrittle nature of advanced ceramics and the re
37、lease of strainenergy contribute to the potential release of uncontrolledfragments upon fracture. Means for containment and retentionof these fragments for safety as well as later fractographicreconstruction and analysis are recommended.8. Test Specimen8.1 Test Specimen GeometryTensile test specimen
38、s asdiscussed in 8.1 of Test Method C1273 may be used for cyclicfatigue testing as long as they meet the requirements of thispractice and Test Method C1273.8.2 Test Specimen PreparationTest specimen fabricationand preparation methods as discussed in 8.2 of Test MethodC1273 may be used for cyclic fat
39、igue testing as long as theymeet the requirements of this practice and Test Method C1273.8.3 Handling PrecautionExercise care in storing andhandling finished specimens to avoid the introduction ofrandom and severe flaws. In addition, give attention to preteststorage of test specimens in controlled e
40、nvironments or desic-cators to avoid unquantifiable environmental degradation ofspecimens prior to testing. If conditioning is required, condi-tion or test the specimens, or both in a room or enclosed spacemaintained at 63C and 610 % relative humidity measured inaccordance with Test Method E337.8.4
41、Number of Test SpecimensThe number of test speci-mens will depend on the purpose of the particular test. Refer toSTP 91A as a guide to determining the number of testspecimens and statistical methods.8.5 Valid TestsA valid individual test is one which meetsall the following requirements: all the test
42、ing requirements ofthis practice and Test Method C1273, and for a test involvinga failed test specimen, failure occurs in the uniformly stressedgage section unless those tests failing outside the gage sectionare interpreted as interrupted tests for the purpose of censoredtest analyses.9. Procedure9.
43、1 Test Specimen DimensionsDetermine the diameter orthe thickness and width of the gage section of each testspecimen, or both, to within 0.02 mm on at least three differentcross-sectional planes in the gage section. To avoid damage inthe critical gage section area make these measurements eitheroptica
44、lly (for example, using an optical comparator) or me-chanically using a flat, anvil-type micrometer. In either case,the resolution of the instrument shall be as specified in 6.7.Exercise extreme caution to prevent damage to the testspecimen gage section. Record and report the measured dimen-sions an
45、d locations of the measurements for use in thecalculation of the tensile stress at fracture. Use the average ofthe multiple measurements in the stress calculations.NOTE 1Ball-tipped or sharp-anvil micrometers may damage the testspecimen surface by inducing localized cracking and, therefore, are notr
46、ecommended.9.1.1 Conduct periodic, if not 100 %, inspection/measurements of all test specimens and test specimen dimen-sions to ensure compliance with the drawing specifications.High-resolution optical methods (for example, an opticalcomparator) or high-resolution digital point contact methods(for e
47、xample coordinate measurement machine) are satisfac-tory as long as the equipment meets the specifications in 6.7.The frequency of occurrence of gage section fractures andbending in the gage section are dependent on proper overalltest specimen dimensions within the required tolerances.9.1.2 In some
48、cases it is desirable, but not required, tomeasure surface finish to quantify the surface condition. Suchmethods as contacting profilometry can be used to determinesurface roughness of the gage section. When quantified, reportthe direction(s) of the surface roughness measurement andsurface roughness
49、 as average surface roughness, Ra, or root-mean-square surface roughness, Rq, at a minimum.9.2 Test Modes and Rates:9.2.1 GeneralTest modes and rates can have distinct andstrong influences on the cyclic fatigue behavior of advancedceramics even at ambient temperatures depending on testenvironment or condition of the test specimen. Test modes mayinvolve load, displacement, or strain control. Maximum andminimum test levels as well as frequency and wave form shapewill depend on the purpose for which the
