1、Designation: C 1359 05Standard Test Method forMonotonic Tensile Strength Testing of Continuous Fiber-Reinforced Advanced Ceramics With Solid RectangularCross-Section Test Specimens at Elevated Temperatures1This standard is issued under the fixed designation C 1359; the number immediately following t
2、he 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method cover
3、s the determination of tensilestrength including stress-strain behavior under monotonicuniaxial loading of continuous fiber-reinforced advanced ce-ramics at elevated temperatures. This test method addresses,but is not restricted to, various suggested test specimengeometries as listed in the appendix
4、. In addition, test specimenfabrication methods, testing modes (force, displacement, orstrain control), testing rates (force rate, stress rate, displace-ment rate, or strain rate), allowable bending, temperaturecontrol, temperature gradients, and data collection and report-ing procedures are address
5、ed. Tensile strength as used in thistest method refers to the tensile strength obtained undermonotonic uniaxial loading where monotonic refers to acontinuous nonstop test rate with no reversals from testinitiation to final fracture.1.2 This test method applies primarily to advanced ceramicmatrix com
6、posites with continuous fiber reinforcement: uni-directional (1-D), bi-directional (2-D), and tri-directional (3-D)or other multi-directional reinforcements. In addition, this testmethod may also be used with glass (amorphous) matrixcomposites with 1-D, 2-D, 3-D and other multi-directionalcontinuous
7、 fiber reinforcements. This test method does notdirectly address discontinuous fiber-reinforced, whisker-reinforced, or particulate-reinforced ceramics, although the testmethods detailed here may be equally applicable to thesecomposites.1.3 The values stated in SI units are to be regarded as thestan
8、dard and are in accordance with SI10-02 IEEE/ASTM SI10.1.4 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
9、 of regulatory limitations prior to use. Refer to Section 7for specific precautions.2. Referenced Documents2.1 ASTM Standards:2C 1145 Terminology of Advanced CeramicsD 3878 Terminology of High Modulus Reinforcing Fibersand Their CompositesE4 Practices for Force Verification of Testing MachinesE6 Ter
10、minology Relating to Methods of Mechanical Test-ingE21 Practice for Elevated Temperature Tension Tests ofMetallic MaterialsE83 Practice for Verification and Classification of Exten-someter SystemE 220 Test Method for Calibration of Thermocouples byComparison TechniquesE 337 Test Method for Measuring
11、 Humidity with a Psy-chrometer (the Measurement of Wet-and Dry-Bulb Tem-peratures)E 1012 Practice for Verification of Specimen AlignmentUnder Tensile LoadingSI10-02 IEEE/ASTM SI 10 American National Standardfor Use of the International System of Units (SI): TheModern Metric System3. Terminology3.1 D
12、efinitions:3.1.1 Definitions of terms relating to tensile testing, ad-vanced ceramics, fiber-reinforced composites as they appear inTerminology E6, Terminology C 1145, and TerminologyD 3878, respectively, apply to the terms used in this testmethod. Pertinent definitions are shown in the following wi
13、ththe appropriate source given in parentheses. Additional termsused in conjunction with this test method are defined in 3.2.3.2 Definitions of Terms Specific to This Standard:1This test method is under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and is the direct responsibility of Sub
14、committee C28.07 onCeramic Matrix Composites.Current edition approved June 1, 2005. Published July 2005. Originally approvedin 1996. Last previous edition approved in 2000 as C 1359 96 (2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser
15、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1 advanced ceramic, nhighly engineered, high-perfo
16、rmance predominately nonmetallic, inorganic, ceramicmaterial having specific functional attributes. C 11453.2.2 axial strain LL1, naverage longitudinal strainsmeasured at the surface on opposite sides of the longitudinalaxis of symmetry of the specimen by two strain-sensingdevices located at the mid
17、 length of the reduced section.E 10123.2.3 bending strain LL1, ndifference between thestrain at the surface and the axial strain. In general, the bendingstrain varies from point to point around and along the reducedsection of the specimen. E 10123.2.4 breaking force F, nforce at which fracture occur
18、s.E63.2.5 ceramic matrix composite, nmaterial consisting oftwo or more materials (insoluble in one another), in which themajor, continuous component (matrix component) is a ceramic,while the secondary component(s) (reinforcing component)may be ceramic, glass-ceramic, glass, metal, or organic innatur
19、e. These components are combined on a macroscale toform a useful engineering material possessing certain proper-ties or behavior not possessed by the individual constituents.3.2.6 continuous fiber-reinforced ceramic matrix composite(CFCC), nceramic matrix composite in which the reinforc-ing phase co
20、nsists of a continuous fiber, continuous yarn, or awoven fabric.3.2.7 fracture strength FL2, ntensile stress that thematerial sustains at the instant of fracture. Fracture strength iscalculated from the force at fracture during a tension testcarried to rupture and the original cross-sectional area o
21、f thespecimen. E63.2.7.1 DiscussionIn some cases, the fracture strengthmay be identical to the tensile strength if the force at fractureis the maximum for the test.3.2.8 gage length L, noriginal length of that portion ofthe specimen over which strain or change of length is deter-mined. E63.2.9 matri
22、x-cracking stress FL2, napplied tensilestress at which the matrix cracks into a series of roughlyparallel blocks normal to the tensile stress.3.2.9.1 DiscussionIn some cases, the matrix crackingstress may be indicated on the stress-strain curve by deviationfrom linearity (proportional limit) or incr
23、emental drops in thestress with increasing strain. In other cases, especially withmaterials which do not possess a linear portion of the stress-strain curve, the matrix cracking stress may be indicated as thefirst stress at which a permanent offset strain is detected in theunloading stress-strain (e
24、lastic limit) curve.3.2.10 modulus of elasticity FL2, nratio of stress tocorresponding strain below the proportional limit. E63.2.11 modulus of resilience FLL3, nstrain energy perunit volume required to elastically stress the material from zeroto the proportional limit indicating the ability of the
25、material toabsorb energy when deformed elastically and return it whenunloaded.3.2.12 modulus of toughness FLL3, nstrain energy perunit volume required to stress the material from zero to finalfracture indicating the ability of the material to absorb energybeyond the elastic range (that is, damage to
26、lerance of thematerial).3.2.12.1 DiscussionThe modulus of toughness can also bereferred to as the cumulative damage energy and as such isregarded as an indication of the ability of the material to sustaindamage rather than as a material property. Fracture mechanicsmethods for the characterization of
27、 CFCCs have not beendeveloped. The determination of the modulus of toughness asprovided in this test method for the characterization of thecumulative damage process in CFCCs may become obsoletewhen fracture mechanics methods for CFCCs become avail-able.3.2.13 proportional limit stress FL2, ngreatest
28、 stresswhich a material is capable of sustaining without any deviationfrom proportionality of stress to strain (Hookes law). E63.2.13.1 DiscussionMany experiments have shown thatvalues observed for the proportional limit vary greatly with thesensitivity and accuracy of the testing equipment, eccentr
29、icityof loading, the scale to which the stress-strain diagram isplotted, and other factors. When determination of proportionallimit is required, the procedure and sensitivity of the testequipment shall be specified.3.2.14 percent bending, nbending strain times 100 di-vided by the axial strain. E 101
30、23.2.15 slow crack growth (SCG), nsubcritical crackgrowth (extension) which may result from, but is not restrictedto, such mechanisms as environmentally-assisted stress corro-sion or diffusive crack growth. C 11453.2.16 tensile strength FL2, nmaximum tensile stresswhich a material is capable of sust
31、aining. Tensile strength iscalculated from the maximum force during a tension testcarried to rupture and the original cross-sectional area of thespecimen. E64. Significance and Use4.1 This test method may be used for material development,material comparison, quality assurance, characterization, reli
32、-ability assessment, and design data generation.4.2 Continuous fiber-reinforced ceramic matrix compositesgenerally characterized by crystalline matrices and ceramicfiber reinforcements are candidate materials for structuralapplications requiring high degrees of wear and corrosionresistance, and elev
33、ated-temperature inherent damage toler-ance (that is, toughness). In addition, continuous fiber-reinforced glass (amorphous) matrix composites are candidatematerials for similar but possibly less-demanding applications.Although flexural test methods are commonly used to evaluatestrengths of monolith
34、ic advanced ceramics, the non-uniformstress distribution of the flexure test specimen in addition todissimilar mechanical behavior in tension and compression forCFCCs leads to ambiguity of interpretation of strength resultsobtained from flexure tests for CFCCs. Uniaxially-loadedtensile-strength test
35、s provide information on mechanical be-havior and strength for a uniformly stressed material.4.3 Unlike monolithic advanced ceramics that fracture cata-strophically from a single dominant flaw, CFCCs generallyexperience 8graceful (that is, non-catastrophic, ductile-likestress-strain behavior) fractu
36、re from a cumulative damageC1359052process. Therefore, the volume of material subjected to auniform tensile stress for a single uniaxially-loaded tensile testmay not be as significant a factor in determining the ultimatestrengths of CFCCs. However, the need to test a statisticallysignificant number
37、of tensile test specimens is not obviated.Therefore, because of the probabilistic nature of the strengthsof the brittle fibers and matrices of CFCCs, a sufficient numberof test specimens at each testing condition is required forstatistical analysis and design. Studies to determine the influ-ence of
38、test specimen volume or surface area on strengthdistributions for CFCCs have not been completed. It should benoted that tensile strengths obtained using different recom-mended tensile test specimen geometries with different vol-umes of material in the gage sections may be different due tothese volum
39、e differences.4.4 Tensile tests provide information on the strength anddeformation of materials under uniaxial tensile stresses. Uni-form stress states are required to effectively evaluate anynon-linear stress-strain behavior that may develop as the resultof cumulative damage processes (for example,
40、 matrix cracking,matrix/fiber debonding, fiber fracture, delamination, and soforth) that may be influenced by testing mode, testing rate,effects of processing or combinations of constituent materials,environmental influences, or elevated temperatures. Some ofthese effects may be consequences of stre
41、ss corrosion or subcritical (slow) crack growth that can be minimized by testing atsufficiently rapid rates as outlined in this test method.4.5 The results of tensile tests of test specimens fabricatedto standardized dimensions from a particular material orselected portions of a part, or both, may n
42、ot totally representthe strength and deformation properties of the entire, full-sizeend product or its in-service behavior in different environmentsor various elevated temperatures.4.6 For quality control purposes, results derived from stan-dardized tensile test specimens may be considered indicativ
43、e ofthe response of the material from which they were taken for theparticular primary processing conditions and post-processingheat treatments.4.7 The tensile behavior and strength of a CFCC aredependent on its inherent resistance to fracture, the presence offlaws, or damage accumulation processes,
44、or both. Analysis offracture surfaces and fractography, though beyond the scope ofthis test method, is recommended.5. Interferences5.1 Test environment (vacuum, inert gas, ambient air, etc.)including moisture content (for example, relative humidity)may have an influence on the measured tensile stren
45、gth. Inparticular, the behavior of materials susceptible to slow crackgrowth fracture will be strongly influenced by test environ-ment, testing rate, and elevated temperature of the test.Conduct tests to evaluate the maximum strength potential of amaterial in inert environments or at sufficiently ra
46、pid testingrates, or both, to minimize slow crack growth effects. Con-versely, conduct tests in environments or at test modes, or both,and rates representative of service conditions to evaluatematerial performance under use conditions. Monitor and reportrelative humidity (RH) and temperature when te
47、sting is con-ducted in uncontrolled ambient air with the intent of evaluatingmaximum strength potential. Testing at humidity levels 65 %RH is not recommended.5.2 Surface preparation of test specimens, although nor-mally not considered a major concern in CFCCs, can introducefabrication flaws which ma
48、y have pronounced effects on tensilemechanical properties and behavior (for example, shape andlevel of the resulting stress-strain curve, tensile strength andstrain, proportional limit stress and strain, and so forth).Machining damage introduced during test specimen prepara-tion can be either a rand
49、om interfering factor in the determi-nation of ultimate strength of pristine material (that is, increasefrequency of surface-initiated fractures compared to volume-initiated fractures), or an inherent part of the strength charac-teristics to be measured. Surface preparation can also lead tothe introduction of residual stresses. Universal or standardizedmethods for surface preparation do not exist. In addition, thenature of fabrication used for certain composites (for example,chemical vapor infiltration or hot pressing) may require t
