ASTM C1161-18

Standard Test Method for Flexural Strength of Advanced Ceramics at Ambient Temperature

SIGNIFICANCE AND USE
4.1 This test method may be used for material development, quality control, characterization, and design data generation purposes. This test method is intended to be used with ceramics whose strength is 50 MPa (~7 ksi) or greater.  
4.2 The flexure stress is computed based on simple beam theory with assumptions that the material is isotropic and homogeneous, the moduli of elasticity in tension and compression are identical, and the material is linearly elastic. The average grain size should be no greater than one-fiftieth of the beam thickness. The homogeneity and isotropy assumption in the standard rule out the use of this test for continuous fiber-reinforced ceramics.  
4.3 Flexural strength of a group of test specimens is influenced by several parameters associated with the test procedure. Such factors include the loading rate, test environment, specimen size, specimen preparation, and test fixtures. Specimen sizes and fixtures were chosen to provide a balance between practical configurations and resulting errors, as discussed in MIL-STD-1942(MR) and Refs (1, 2).4 Specific fixture and specimen configurations were designated in order to permit ready comparison of data without the need for Weibull-size scaling.  
4.4 The flexural strength of a ceramic material is dependent on both its inherent resistance to fracture and the size and severity of flaws. Variations in these cause a natural scatter in test results for a sample of test specimens. Fractographic analysis of fracture surfaces, although beyond the scope of this standard, is highly recommended for all purposes, especially if the data will be used for design as discussed in MIL-STD-1942(MR) and Refs (2-5) and Practices C1322 and C1239.  
4.5 The three-point test configuration exposes only a very small portion of the specimen to the maximum stress. Therefore, three-point flexural strengths are likely to be much greater than four-point flexural strengths. Three-point flexure has some advantages. It uses sim...
SCOPE
1.1 This test method covers the determination of flexural strength of advanced ceramic materials at ambient temperature. Four-point-1/4-point and three-point loadings with prescribed spans are the standard as shown in Fig. 1. Rectangular specimens of prescribed cross-section sizes are used with specified features in prescribed specimen-fixture combinations. Test specimens may be 3 by 4 by 45 to 50 mm in size that are tested on 40-mm outer span four-point or three-point fixtures. Alternatively, test specimens and fixture spans half or twice these sizes may be used. The method permits testing of machined or as-fired test specimens. Several options for machining preparation are included: application matched machining, customary procedure, or a specified standard procedure. This method describes the apparatus, specimen requirements, test procedure, calculations, and reporting requirements. The test method is applicable to monolithic or particulate- or whisker-reinforced ceramics. It may also be used for glasses. It is not applicable to continuous fiber-reinforced ceramic composites.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 31-Dec-2017
• ICS: 81.060.20 - Ceramic products
• Technical Committee: C28 - Advanced Ceramics
• Drafting Committee: C28.01 - Mechanical Properties and Performance

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: C1161 − 18
Standard Test Method for
Flexural Strength of Advanced Ceramics at Ambient
1
Temperature
This standard is issued under the fixed designation C1161; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2
1.1 This test method covers the determination of flexural 2.1 ASTM Standards:
strength of advanced ceramic materials at ambient temperature. C1239 Practice for Reporting Uniaxial Strength Data and
1
Four-point- ⁄4-point and three-point loadings with prescribed Estimating Weibull Distribution Parameters for Advanced
spans are the standard as shown in Fig. 1. Rectangular Ceramics
specimens of prescribed cross-section sizes are used with C1322 Practice for Fractography and Characterization of
specified features in prescribed specimen-fixture combinations. Fracture Origins in Advanced Ceramics
Test specimens may be 3 by 4 by 45 to 50 mm in size that are C1368 Test Method for Determination of Slow Crack
tested on 40-mm outer span four-point or three-point fixtures. Growth Parameters of Advanced Ceramics by Constant
Alternatively, test specimens and fixture spans half or twice Stress Rate Strength Testing at Ambient Temperature
these sizes may be used. The method permits testing of E4 Practices for Force Verification of Testing Machines
machined or as-fired test specimens. Several options for E337 Test Method for Measuring Humidity with a Psy-
machining preparation are included: application matched chrometer (the Measurement of Wet- and Dry-Bulb Tem-
machining, customary procedure, or a specified standard pro- peratures)
3
cedure. This method describes the apparatus, specimen
2.2 Military Standard:
requirements, test procedure, calculations, and reporting re-
MIL-STD-1942(MR) Flexural Strength of High Perfor-
quirements. The test method is applicable to monolithic or
mance Ceramics at Ambient Temperature
particulate- or whisker-reinforced ceramics. It may also be
used for glasses. It is not applicable to continuous fiber- 3. Terminology
reinforced ceramic composites.
3.1 Definitions:
1.2 The values stated in SI units are to be regarded as the 3.1.1 complete gage section, n—the portion of the specimen
standard. The values given in parentheses are for information
between the two outer bearings in four-point flexure and
only. three-point flexure fixtures.
1.3 This standard does not purport to address all of the
NOTE 1—In this standard, the complete four-point flexure gage section
safety concerns, if any, associated with its use. It is the is twice the size of the inner gage section. Weibull statistical analysis only
includes portions of the specimen volume or surface which experience
responsibility of the user of this standard to establish appro-
tensile stresses.
priate safety, health, and environmental practices and deter-
–2
3.1.2 flexural strength, [FL ], n—a measure of the ultimate
mine the applicability of regulatory limitations prior to use.
strength of a specified beam in bending.
1.4 This international standard was developed in accor-
1
dance with internationally recognized principles on standard-
3.1.3 four-point- ⁄4-point flexure, n—configuration of flex-
ization established in the Decision on Principles for the
ural strength testing where a specimen is symmetrically loaded
Development of International Standards, Guides and Recom-
at two locations that are situated one-quarter of the overall span
mendations issued by the World Trade Organization Technical
away from the outer two support bearings (see Fig. 1).
Barriers to Trade (TBT) Committee.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
1
This test method is under the jurisdiction of ASTM Committee C28 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Advanced Ceramics and is the direct responsibility of Subcommittee C28.01 on Standards volume information, refer to the standard’s Document Summary page on
Mechanical Properties and Performance. the ASTM website.
3
Current edition approved Jan. 1, 2018. Published February 2018. Originally Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
approved in 1990. Last previous edition approved in 2013 as C1161 – 13. DOI: Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
10.1520/C1161-18. www.dodssp.daps.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1161 − 13 C1161 − 18
Standard Test Method for
Flexural Strength of Advanced Ceramics at Ambient
1
Temperature
This standard is issued under the fixed designation C1161; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This test method covers the determination of flexural strength of advanced ceramic materials at ambient temperature.
1
Four-point–Four-point- ⁄4 point -point and three-point loadings with prescribed spans are the standard as shown in Fig. 1.
Rectangular specimens of prescribed cross-section sizes are used with specified features in prescribed specimen-fixture
combinations. Test specimens may be 3 by 4 by 45 to 50 mm in size that are tested on 40 mm 40-mm outer span four-point or
three-point fixtures. Alternatively, test specimens and fixture spans half or twice these sizes may be used. The method permits
testing of machined or as-fired test specimens. Several options for machining preparation are included: application matched
machining, customary procedure, or a specified standard procedure. This method describes the apparatus, specimen requirements,
test procedure, calculations, and reporting requirements. The test method is applicable to monolithic or particulate- or
whisker-reinforced ceramics. It may also be used for glasses. It is not applicable to continuous fiber-reinforced ceramic composites.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
C1239 Practice for Reporting Uniaxial Strength Data and Estimating Weibull Distribution Parameters for Advanced Ceramics
C1322 Practice for Fractography and Characterization of Fracture Origins in Advanced Ceramics
C1368 Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress Rate
Strength Testing at Ambient Temperature
E4 Practices for Force Verification of Testing Machines
E337 Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures)
3
2.2 Military Standard:
MIL-STD-1942 MIL-STD-1942(MR) (MR) Flexural Strength of High Performance Ceramics at Ambient Temperature
3. Terminology
3.1 Definitions:
3.1.1 complete gage section, n—the portion of the specimen between the two outer bearings in four-point flexure and three-point
flexure fixtures.
1
This test method is under the jurisdiction of ASTM Committee C28 on Advanced Ceramics and is the direct responsibility of Subcommittee C28.01 on Mechanical
Properties and Performance.
Current edition approved Aug. 1, 2013Jan. 1, 2018. Published September 2013February 2018. Originally approved in 1990. Last previous edition approved in 20082013
ε1
as C1161 – 02c (2008)13. . DOI: 10.1520/C1161-13.10.1520/C1161-18.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://www.dodssp.daps.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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C1161 − 18
NOTE 1—Configuration:
A: L = 20 mm
B: L = 40 mm
C: L = 80 mm
1
FIG. 1 The Four-Point–Four-Point- ⁄4 Point -Point and Three-Point Fixture Configuration
...