ASTM C1275-00(2005)e1
(Test Method)Standard Test Method for Monotonic Tensile Behavior of Continuous Fiber-Reinforced Advanced Ceramics with Solid Rectangular Cross-Section Test Specimens at Ambient Temperature
Standard Test Method for Monotonic Tensile Behavior of Continuous Fiber-Reinforced Advanced Ceramics with Solid Rectangular Cross-Section Test Specimens at Ambient Temperature
SCOPE
1.1 This test method covers the determination of tensile behavior including tensile strength and stress-strain response under monotonic uniaxial loading of continuous fiber-reinforced advanced ceramics at ambient temperature. This test method addresses, but is not restricted to, various suggested test specimen geometries as listed in the appendix. In addition, specimen fabrication methods, testing modes (force, displacement, or strain control), testing rates (force rate, stress rate, displacement rate, or strain rate), allowable bending, and data collection and reporting procedures are addressed. Note that tensile strength as used in this test method refers to the tensile strength obtained under monotonic uniaxial loading where monotonic refers to a continuous nonstop test rate with no reversals from test initiation to final fracture.
1.2 This test method applies primarily to all advanced ceramic matrix composites with continuous fiber reinforcement: uni-directional (1-D), bi-directional (2-D), and tri-directional (3-D). In addition, this test method may also be used with glass (amorphous) matrix composites with 1-D, 2-D, and 3-D continuous fiber reinforcement. This test method does not address directly discontinuous fiber-reinforced, whisker-reinforced or particulate-reinforced ceramics, although the test methods detailed here may be equally applicable to these composites.
1.3 Values expressed in this test method are in accordance with the International System of Units (SI) and IEEE/ASTM SI 10.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Section 7 and 8.2.5.2.
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Designation:C1275–00(Reapproved 2005)
Standard Test Method for
Monotonic Tensile Behavior of Continuous Fiber-Reinforced
Advanced Ceramics with Solid Rectangular Cross-Section
Test Specimens at Ambient Temperature
This standard is issued under the fixed designation C1275; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—The Warning note in 8.2.5.2 was editorially updated in June 2005.
1. Scope 2. Referenced Documents
1.1 This test method covers the determination of tensile 2.1 ASTM Standards:
behavior including tensile strength and stress-strain response C1145 Terminology of Advanced Ceramics
under monotonic uniaxial loading of continuous fiber- C1239 Practice for Reporting Uniaxial Strength Data and
reinforcedadvancedceramicsatambienttemperature.Thistest Estimating Weibull Distribution Parameters for Advanced
method addresses, but is not restricted to, various suggested Ceramics
test specimen geometries as listed in the appendix. In addition, D3039/D3039M Test Method for Tensile Properties of
specimen fabrication methods, testing modes (force, displace- Polymer Matrix Composite Materials
ment, or strain control), testing rates (force rate, stress rate, D3379 Test Method for Tensile Strength and Young’s
displacement rate, or strain rate), allowable bending, and data Modulus for High-Modulus Single-Filament Materials
collection and reporting procedures are addressed. Note that D3878 Terminology for Composite Materials
tensile strength as used in this test method refers to the tensile E4 Practices for Force Verification of Testing Machines
strength obtained under monotonic uniaxial loading where E6 TerminologyRelatingtoMethodsofMechanicalTesting
monotonic refers to a continuous nonstop test rate with no E83 Practice for Verification and Classification of Exten-
reversals from test initiation to final fracture. someter Systems
1.2 This test method applies primarily to all advanced E177 Practice for Use of the Terms Precision and Bias in
ceramic matrix composites with continuous fiber reinforce- ASTM Test Methods
ment: uni-directional (1-D), bi-directional (2-D), and tri- E337 Test Method for Measuring Humidity with a Psy-
directional (3-D). In addition, this test method may also be chrometer (the Measurement of Wet- and Dry-Bulb Tem-
usedwithglass(amorphous)matrixcompositeswith1-D,2-D, peratures)
and 3-D continuous fiber reinforcement.This test method does E691 Practice for Conducting an Interlaboratory Study to
not address directly discontinuous fiber-reinforced, whisker- Determine the Precision of a Test Method
reinforced or particulate-reinforced ceramics, although the test E1012 PracticeforVerificationofTestFrameandSpecimen
methods detailed here may be equally applicable to these Alignment Under Tensile and Compressive Axial Force
composites. Application
1.3 Values expressed in this test method are in accordance IEEE/ASTM SI 10 American National Standard for Use of
withtheInternationalSystemofUnits(SI)andIEEE/ASTMSI the International System of Units (SI): The Modern Metric
10 . System
1.4 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 3.1 Definitions—The definitions of terms relating to tensile
testingappearinginTerminologyE6applytothetermsusedin
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific hazard this test method. The definitions of terms relating to advanced
ceramics appearing in Terminology C1145 apply to the terms
statements are given in Section 7 and 8.2.5.2.
used in this test method. The definitions of terms relating to
This practice is under the jurisdiction ofASTM Committee C28 onAdvanced
Ceramics and is the direct responsibility of Subcommittee C28.07 on Ceramic
Matrix Composites. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 1, 2005. Published June 2005. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1994. Last previous edition approved in 2000 as C1275–00. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1275-00R05E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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C1275–00 (2005)
fiber reinforced composites appearing in Terminology D3878 regardedasanindicationoftheabilityofthematerialtosustain
applytothetermsusedinthistestmethod.Pertinentdefinitions damage rather than as a material property. Fracture mechanics
as listed in Practice E1012, Terminology C1145, Terminology methods for the characterization of CFCCs have not been
D3878, and Terminology E6 are shown in the following with developed. The determination of the modulus of toughness as
the appropriate source given in parentheses. Additional terms provided in this test method for the characterization of the
used in conjunction with this test method are defined in the cumulative damage process in CFCCs may become obsolete
following: when fracture mechanics methods for CFCCs become avail-
3.1.1 advancedceramic,n—highlyengineered,highperfor- able.
3.1.14 proportional limit stress—greatest stress that a ma-
mance predominantly nonmetallic, inorganic, ceramic material
having specific functional attributes. C1145 terial is capable of sustaining without any deviation from
proportionality of stress to strain (Hooke’s law).
3.1.2 axial strain—average longitudinal strains measured at
3.1.15 Discussion—Many experiments have shown that
the surface on opposite sides of the longitudinal axis of
valuesobservedfortheproportionallimitvarygreatlywiththe
symmetry of the specimen by two strain-sensing devices
sensitivity and accuracy of the testing equipment, eccentricity
located at the mid length of the reduced section. E1012
of loading, the scale to which the stress-strain diagram is
3.1.3 bending strain—difference between the strain at the
plotted, and other factors. When determination of proportional
surface and the axial strain. In general, the bending strain
limit is required, the procedure and sensitivity of the test
variesfrompointtopointaroundandalongthereducedsection
equipment should be specified. (See Terminology E6.)
of the specimen. E1012
3.1.16 percent bending—bending strain times 100 divided
3.1.4 breaking force—force at which fracture occurs. E6
by the axial strain. E1012
3.1.5 ceramicmatrixcomposite—materialconsistingoftwo
3.1.17 slow crack growth—subcritical crack growth (exten-
or more materials (insoluble in one another), in which the
sion) which may result from, but is not restricted to, such
major,continuouscomponent(matrixcomponent)isaceramic,
mechanisms as environmentally-assisted stress corrosion or
whilethesecondarycomponent/s(reinforcingcomponent)may
diffusive crack growth.
be ceramic, glass-ceramic, glass, metal or organic in nature.
3.1.18 tensile strength—maximum tensile stress which a
These components are combined on a macroscale to form a
material is capable of sustaining. Tensile strength is calculated
useful engineering material possessing certain properties or
fromthemaximumloadduringatensiontestcarriedtorupture
behavior not possessed by the individual constituents.
and the original cross-sectional area of the specimen. E6
3.1.6 continuous fiber-reinforced ceramic matrix composite
(CFCC)—ceramic matrix composite in which the reinforcing
4. Significance and Use
phase consists of a continuous fiber, continuous yarn, or a
4.1 Thistestmethodmaybeusedformaterialdevelopment,
woven fabric.
material comparison, quality assurance, characterization, and
3.1.7 gage length—original length of that portion of the
design data generation.
specimen over which strain or change of length is determined.
4.2 Continuous fiber-reinforced ceramic matrix composites
E6
generally characterized by fine grain sized (<50 µm) matrices
3.1.8 matrix-cracking stress—applied tensile stress at
and ceramic fiber reinforcements are candidate materials for
whichthematrixcracksintoaseriesofroughlyparallelblocks
structural applications requiring high degrees of wear and
normal to the tensile stress.
corrosion resistance, and high-temperature inherent damage
3.1.9 Discussion—Insomecases,thematrixcrackingstress
tolerance (that is, toughness). In addition, continuous fiber-
may be indicated on the stress-strain curve by deviation from
reinforced glass (amorphous) matrix composites are candidate
linearity (proportional limit) or incremental drops in the stress
materials for similar but possibly less-demanding applications.
with increasing strain. In other cases, especially with materials
Although flexural test methods are commonly used to evaluate
whichdonotpossessalinearportionofthestress-straincurve,
strengths of monolithic advanced ceramics, the non-uniform
thematrixcrackingstressmaybeindicatedasthefirststressat
stress distribution of the flexure specimen in addition to
which a permanent offset strain is detected in the unloading
dissimilar mechanical behavior in tension and compression for
stress-strain (elastic limit).
CFCCs lead to ambiguity of interpretation of strength results
3.1.10 modulus of elasticity—ratio of stress to correspond-
obtained from flexure tests for CFCCs. Uniaxial-loaded tensile
ing strain below the proportional limit. E6
strength tests provide information on mechanical behavior and
3.1.11 modulus of resilience—strain energy per unit vol-
strength for a uniformly-stressed material.
ume required to elastically stress the material from zero to the
4.3 Unlike monolithic advanced ceramics which fracture
proportional limit indicating the ability of the material to
catastrophicallyfromasingledominantflaw,CFCCsgenerally
absorb energy when deformed elastically and return it when
experience “graceful” fracture from a cumulative damage
unloaded.
process. Therefore, the volume of material subjected to a
3.1.12 modulusoftoughness—strainenergyperunitvolume
uniform tensile stress for a single uniaxially-loaded tensile test
required to stress the material from zero to final fracture
may not be as significant a factor in determining the ultimate
indicating the ability of the material to absorb energy beyond
strengths of CFCCs. However, the need to test a statistically
the elastic range (that is, damage tolerance of the material).
significant number of tensile specimens is not obviated.There-
3.1.13 Discussion— The modulus of toughness can also be fore, because of the probabilistic nature of the strength distri-
referred to as the cumulative damage energy and as such is butionsofthebrittlematricesofCFCCs,asufficientnumberof
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C1275–00 (2005)
specimens at each testing condition is required for statistical damage introduced during specimen preparation can be either
analysisanddesign.Studiestodeterminetheexactinfluenceof a random interfering factor in the determination of ultimate
specimenvolumeonstrengthdistributionsforCFCCshavenot
strength of pristine material (that is, increased frequency of
been completed. It should be noted that tensile strengths surface initiated fractures compared to volume initiated frac-
obtained using different recommended tensile specimens with
tures), or an inherent part of the strength characteristics to be
different volumes of material in the gage sections may be
measured.Surfacepreparationcanalsoleadtotheintroduction
different due to these volume differences.
of residual stresses. Universal or standardized test methods of
4.4 Tensile tests provide information on the strength and
surface preparation do not exist. It should be understood that
deformation of materials under uniaxial tensile stresses. Uni-
final machining steps may, or may not negate machining
form stress states are required to effectively evaluate any
damage introduced during the initial machining. Thus, speci-
non-linear stress-strain behavior which may develop as the
men fabrication history may play an important role in the
result of cumulative damage processes (for example, matrix
measured strength distributions and should be reported. In
cracking, matrix/fiber debonding, fiber fracture, delamination,
addition, the nature of fabrication used for certain composites
etc.) which may be influenced by testing mode, testing rate,
(for example, chemical vapor infiltration or hot pressing) may
processing or alloying effects, or environmental influences.
require the testing of test specimens in the as-processed
Some of these effects may be consequences of stress corrosion
condition (that is, it may not be possible to machine the
or subcritical (slow) crack growth that can be minimized by
specimen faces).
testingatsufficientlyrapidratesasoutlinedinthistestmethod.
5.3 Bending in uniaxial tensile tests can cause or promote
4.5 The results of tensile tests of test specimens fabricated
non-uniformstressdistributionswithmaximumstressesoccur-
to standardized dimensions from a particular material or
ring at the specimen surface leading to non-representative
selected portions of a part, or both, may not totally represent
fracturesoriginatingatsurfacesorneargeometricaltransitions.
the strength and deformation properties of the entire, full-size
In addition, if deformations or strains are measured at surfaces
end product or its in-service behavior in different environ-
where maximum or minimum stresses occur, bending may
ments.
introduce over or under measurement of strains depending on
4.6 For quality control purposes, results derived from stan-
the location of the strain-measuring device on the specimen.
dardizedtensiletestspecimensmaybeconsideredindicativeof
Similarly, fracture from surface flaws may be accentuated or
the response of the material from which they were taken for,
suppressed by the presence of the non-uniform stresses caused
given primary processing conditions and post-processing heat
by bending.
treatments.
5.4 Fractures that initiate outside the uniformly-stressed
4.7 The tensile behavior and strength of a CFCC are
gage section of a test specimen may be due to factors such as
dependentonitsinherentresistancetofracture,thepresenceof
stress concentrations or geometrical transitions, extraneous
flaws, or damage accumulation processes, or both.Analysis of
stressesintroducedbygripping,orstrength-limitingfeaturesin
fracturesurfacesandfractography,thoughbeyondthescopeof
the microstructure of the specimen. Such non-gage sectio
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