ASTM C749-92(1996)

Standard Test Method for Tensile Stress-Strain of Carbon and Graphite

SCOPE
1.1 This test method covers the testing of carbon and graphite in tension to obtain the tensile stress-strain behavior, to failure, from which the ultimate strength, the strain to failure, and the elastic moduli may be calculated as may be required for engineering applications. lists suggested sizes of specimens that can be used in the tests.
Note 1—The results of about 400 tests, on file at ASTM as RR:C05-1000, show the ranges of materials that have been tested, the ranges of specimen configurations, and the agreement between the testers.
Note 2—For safety considerations, it is recommended that the chains be surrounded by suitable members so that at failure all parts of the load train behave predictably and do not constitute a hazard for the operator.
1.2 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.
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

General Information

• Status: Historical
• Publication Date: 14-Aug-1992
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.F0 - Manufactured Carbon and Graphite Products

Relations

• Replaced By: ASTM C749-92(2002) - Standard Test Method for Tensile Stress-Strain of Carbon and Graphite
• Effective Date: 15-Aug-1992

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: C 749 – 92 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
1
Tensile Stress-Strain of Carbon and Graphite
This standard is issued under the fixed designation C 749; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Summary of Test Method
4.1 A tensile specimen (Fig. 1) is placed within a load train
1.1 This test method covers the testing of carbon and
assembly made up of precision chains and other machined
graphite in tension to obtain the tensile stress-strain behavior,
parts (Fig. 2). A load is applied to the specimen provided with
to failure, from which the ultimate strength, the strain to
means of measuring strain until it is caused to fracture. This
failure, and the elastic moduli may be calculated as may be
required for engineering applications. Table 1 lists suggested test yields the tensile strength, elastic constants, and strain to
failure of carbons and graphites.
sizes of specimens that can be used in the tests.
NOTE 1—The results of about 400 tests, on file at ASTM as RR:C05- 5. Significance and Use
1000, show the ranges of materials that have been tested, the ranges of
5.1 This test method is intended to be used for both carbons
specimen configurations, and the agreement between the testers.
and graphites whose particle sizes are of the order of 1 mil to
NOTE 2—For safety considerations, it is recommended that the chains
1
⁄4 in. (0.0254 to 6.4 mm) and larger. This wide range of
be surrounded by suitable members so that at failure all parts of the load
carbons and graphites can be tested with uniform gage diam-
train behave predictably and do not constitute a hazard for the operator.
eters with minimum parasitic stresses to provide quality data
1.2 This standard does not purport to address all of the
for use in engineering applications rather than simply for
safety concerns, if any, associated with its use. It is the
quality control. This test method can be easily adapted to
responsibility of the user of this standard to establish appro-
elevated temperature testing of carbons and graphites without
priate safety and health practices and determine the applica-
changing the specimen size or configuration by simply utilizing
bility of regulatory limitations prior to use.
elevated temperature materials for the load train. This test
1.3 The values stated in inch-pound units are to be regarded
method has been utilized for temperatures as high as 4352°F
as the standard. The values given in parentheses are for
(2400°C). The design of the fixtures (Figs. 2-9 and Table 2) and
information only.
description of the procedures are intended to bring about, on
the average, parasitic stresses of less than 5 %. The specimens
2. Referenced Documents
for the different graphites have been designed to ensure
fracture within the gage section commensurate with experi-
2.1 ASTM Standards:
2
enced variability in machining and testing care at different
E 4 Practices for Force Verification of Testing Machines
facilities. The constant gage diameter permits rigorous analyti-
E 6 Terminology Relating to Methods of Mechanical Test-
2
cal treatment.
ing
E 177 Practice for Use of the Terms Precision and Bias in
6. Apparatus
3
ASTM Test Methods
6.1 Testing Machine—The machine used for tensile testing
E 691 Practice for Conducting an Interlaboratory Study to
shall conform to the requirements of Practices E 4. The testing
3
Determine the Precision of a Test Method
machine shall have a load measurement capacity such that the
breaking load of the test specimen falls between 10 and 90 %
3. Terminology
of the scale capacity. This range must be linear to within 1 %
3.1 Definitions—The terms as related to tension testing as
over 1 % increments either by design or by calibration.
given in Terminology E 6 shall be considered as applying to the
6.2 Strain Measurements:
terms used in this test method.
6.2.1 The axial strain can be measured at room temperature
by the use of strain gages, mechanical extensometers, Tucker-
man gages, optical systems, or other devices applied diametri-
1
This test method is under the jurisdiction of ASTM Committee C-5 on
cally opposite in the gage length portion of the specimen. Two
Manufactured Carbon and Graphite Productsand is the direct responsibility of
Subcommittee C05.03 on Property Measurements (Chemical, Physical, and Sam- opposing gages provide some compensation for bending and
pling).
some assurance that it was not severe. D
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