ASTM C1674-11

Standard Test Method for Flexural Strength of Advanced Ceramics with Engineered Porosity (Honeycomb Cellular Channels) at Ambient Temperatures

SIGNIFICANCE AND USE
This test method is used to determine the mechanical properties in flexure of engineered ceramic components with multiple longitudinal hollow channels, commonly described as “honeycomb” channel architectures. The components generally have 30 % or more porosity and the cross-sectional dimensions of the honeycomb channels are on the order of 1 millimeter or greater.
The experimental data and calculated strength values from this test method are used for material and structural development, product characterization, design data, quality control, and engineering/ production specifications.
Note 1—Flexure testing is the preferred method for determining the nominal “tensile fracture” strength of these components, as compared to a compression (crushing) test. A nominal tensile strength is required, because these materials commonly fail in tension under thermal gradient stresses. A true tensile test is difficult to perform on these honeycomb specimens because of gripping and alignment challenges.
The mechanical properties determined by this test method are both material and architecture dependent, because the mechanical response and strength of the porous test specimens are determined by a combination of inherent material properties and microstructure and the architecture of the channel porosity [porosity fraction/relative density, channel geometry (shape, dimensions, cell wall thickness, etc.), anisotropy and uniformity, etc.] in the specimen. Comparison of test data must consider both differences in material/composition properties as well as differences in channel porosity architecture between individual specimens and differences between and within specimen lots.
SCOPE
1.1 This test method covers the determination of the flexural strength (modulus of rupture in bending) at ambient conditions of advanced ceramic structures with 2-dimensional honeycomb channel architectures.
1.2 The test method is focused on engineered ceramic components with longitudinal hollow channels, commonly called “honeycomb” channels. (See Fig. 1.) The components generally have 30 % or more porosity and the cross-sectional dimensions of the honeycomb channels are on the order of 1 millimeter or greater. Ceramics with these honeycomb structures are used in a wide range of applications (catalytic conversion supports (1), high temperature filters (2, 3), combustion burner plates (4), energy absorption and damping (5), etc.). The honeycomb ceramics can be made in a range of ceramic compositionsalumina, cordierite, zirconia, spinel, mullite, silicon carbide, silicon nitride, graphite, and carbon. The components are produced in a variety of geometries (blocks, plates, cylinders, rods, rings).
1.3 The test method describes two test specimen geometries for determining the flexural strength (modulus of rupture) for a porous honeycomb ceramic test specimen (see Fig. 2):
1.3.1 Test Method A—A 4-point or 3-point bending test with user-defined specimen geometries, and
1.3.2 Test Method B—A 4-point- ¼ point bending test with a defined rectangular specimen geometry (13 mm × 25 mm × > 116 mm) and a 90 mm outer support span geometry suitable for cordierite and silicon carbide honeycombs with small cell sizes.
1.4 The test specimens are stressed to failure and the breaking force value, specimen and cell dimensions, and loading geometry data are used to calculate a nominal beam strength, a wall fracture strength, and a honeycomb structure strength.
1.5 Test results are used for material and structural development, product characterization, design data, quality control, and engineering/production specifications.
1.6 The test method is meant for ceramic materials that are linear-elastic to failure in tension. The test method is not applicable to polymer or metallic porous structures that fail in an elastomeric or an elastic-ductile manner.

General Information

• Status: Historical
• Publication Date: 31-Jan-2011
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: C28 - Advanced Ceramics
• Drafting Committee: C28.04 - Applications

Relations

• Replaces: ASTM C1674-08 - Standard Test Method for Flexural Strength of Advanced Ceramics with Engineered Porosity (Honeycomb Cellular Channels) at Ambient Temperatures
• Effective Date: 01-Feb-2011

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:C1674 −11
Standard Test Method for
Flexural Strength of Advanced Ceramics with Engineered
Porosity (Honeycomb Cellular Channels) at Ambient
1
Temperatures
This standard is issued under the fixed designation C1674; 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.
1. Scope* loading geometry data are used to calculate a nominal beam
strength, a wall fracture strength, and a honeycomb structure
1.1 Thistestmethodcoversthedeterminationoftheflexural
strength.
strength(modulusofruptureinbending)atambientconditions
1.5 Test results are used for material and structural
ofadvancedceramicstructureswith2-dimensionalhoneycomb
channel architectures. development, product characterization, design data, quality
control, and engineering/production specifications.
1.2 The test method is focused on engineered ceramic
1.6 The test method is meant for ceramic materials that are
components with longitudinal hollow channels, commonly
linear-elastic to failure in tension. The test method is not
called “honeycomb” channels. (See Fig. 1.) The components
applicable to polymer or metallic porous structures that fail in
generally have 30% or more porosity and the cross-sectional
an elastomeric or an elastic-ductile manner.
dimensions of the honeycomb channels are on the order of 1
millimeter or greater. Ceramics with these honeycomb struc-
1.7 The test method is defined for ambient testing tempera-
tures are used in a wide range of applications (catalytic
tures. No directions are provided for testing at elevated or
2
conversion supports (1), high temperature filters (2, 3),
cryogenic temperatures.
combustion burner plates (4), energy absorption and damping
1.8 The values stated in SI units are to be regarded as
(5), etc.). The honeycomb ceramics can be made in a range of
standard (IEEE/ASTM SI 10). English units are sparsely used
ceramic compositions—alumina, cordierite, zirconia, spinel,
in this standard for product definitions and tool descriptions,
mullite, silicon carbide, silicon nitride, graphite, and carbon.
per the cited references and common practice in the US
The components are produced in a variety of geometries
automotive industry.
(blocks, plates, cylinders, rods, rings).
1.9 This standard does not purport to address all of the
1.3 Thetestmethoddescribestwotestspecimengeometries
safety concerns, if any, associated with its use. It is the
fordeterminingtheflexuralstrength(modulusofrupture)fora
responsibility of the user of this standard to establish appro-
porous honeycomb ceramic test specimen (see Fig. 2):
priate safety and health practices and determine the applica-
1.3.1 Test Method A—A4-pointor3-pointbendingtestwith
bility of regulatory limitations prior to use.
user-defined specimen geometries, and
1
1.3.2 Test Method B—A4-point- ⁄4pointbendingtestwitha
2. Referenced Documents
defined rectangular specimen geometry (13 mm × 25 mm × >
3
2.1 ASTM Standards:
116mm)anda90mmoutersupportspangeometrysuitablefor
C373Test Method for Water Absorption, Bulk Density,
cordierite and silicon carbide honeycombs with small cell
ApparentPorosity,andApparentSpecificGravityofFired
sizes.
Whiteware Products, Ceramic Tiles, and Glass Tiles
1.4 The test specimens are stressed to failure and the
C1145Terminology of Advanced Ceramics
breaking force value, specimen and cell dimensions, and
C1161Test Method for Flexural Strength of Advanced
Ceramics at Ambient Temperature
C1198Test Method for Dynamic Young’s Modulus, Shear
Modulus, and Poisson’s Ratio forAdvanced Ceramics by
1
This test method is under the jurisdiction of ASTM Committee C28 on
Sonic Resonance
Advanced Ceramics and is the direct responsibility of Subcommittee C28.04 on
Applications.
Current edition approved Feb. 1, 2011. Published March 2011. Originally
3
approved in 2008. Last previous edition approved in 2008 as C1674–08. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/C1674-11. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
2
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof Standards volume information, refer to the standard’s Document Summary page on
this standard. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
C1674−11
FIG. 1General Schematics of Typical Honeycomb Ceramic Structures
L = Outer Span Length (for Test Method A, L = User defined; for Test Method B, L=90mm)
1
NOTE 1
...

This document is not anASTM standard and is intended only to provide the user of anASTM 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:C1674–08 Designation: C1674 – 11
Standard Test Method for
Flexural Strength of Advanced Ceramics with Engineered
Porosity (Honeycomb Cellular Channels) at Ambient
1
Temperatures
This standard is issued under the fixed designation C1674; 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.
1. Scope*
1.1 This test method covers the determination of the flexural strength (modulus of rupture in bending) at ambient conditions of
advanced ceramic structures with 2-dimensional honeycomb channel architectures.
1.2 The test method is focused on engineered ceramic components with longitudinal hollow channels, commonly called
“honeycomb” channels. (See Fig. 1.) The components generally have 30 % or more porosity and the cross-sectional dimensions
of the honeycomb channels are on the order of 1 millimeter or greater. Ceramics with these honeycomb structures are used in a
2
wide range of applications (catalytic conversion supports (1), high temperature filters (2, 3), combustion burner plates (4), energy
absorptionanddamping(5),etc.).Thehoneycombceramicscanbemadeinarangeofceramiccompositions—alumina,cordierite,
zirconia, spinel, mullite, silicon carbide, silicon nitride, graphite, and carbon. The components are produced in a variety of
geometries (blocks, plates, cylinders, rods, rings).
1.3 The test method describes two test specimen geometries for determining the flexural strength (modulus of rupture) for a
porous honeycomb ceramic test specimen (see Fig. 2):
1.3.1 Test Method A—A 4-point or 3-point bending test with user-defined specimen geometries, and
1
1.3.2 Test Method B—A 4-point- ⁄4 point bending test with a defined rectangular specimen geometry (13 mm 3 25 mm 3 >
116 mm) and a 90 mm outer support span geometry suitable for cordierite and silicon carbide honeycombs with small cell sizes.
1.4 Thetestspecimensarestressedtofailureandthebreakingforcevalue,specimenandcelldimensions,andloadinggeometry
data are used to calculate a nominal beam strength, a wall fracture strength, and a honeycomb structure strength.
1.5 Test results are used for material and structural development, product characterization, design data, quality control, and
engineering/production specifications.
1.6 The test method is meant for ceramic materials that are linear-elastic to failure in tension. The test method is not applicable
to polymer or metallic porous structures that fail in an elastomeric or an elastic-ductile manner.
1.7 The test method is defined for ambient testing temperatures. No directions are provided for testing at elevated or cryogenic
temperatures.
1.8 The values stated in SI units are to be regarded as standard (IEEE/ASTM SI 10). English units are sparsely used in this
standard for product definitions and tool descriptions, per the cited references and common practice in the US automotive industry.
1.9 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.
2. Referenced Documents
3
2.1 ASTM Standards:
C373 Test Method for Water Absorption, Bulk Density, Apparent Porosity, and Apparent Specific Gravity of Fired Whiteware
Products
C1145 Terminology of Advanced Ceramics
C1161 Test Method for Flexural Strength of Advanced Ceramics at Ambient Temperature
1
This test method is under the jurisdiction of ASTM Committee C28 on Advanced Ceramics and is the direct responsibility of Subcommittee C28.04 on Applications.
Current edition approved June 1, 2008. Published July 2008. DOI: 10.1520/C1674-08.
CurrenteditionapprovedFeb.1,2011.PublishedMarch2011.Originallyapprovedin2008.Lastpreviouseditionapprovedin2008asC1674–08.DOI:10.1520/C1674-11.
2
The boldface numbers in parentheses refer to the list of references at the end of this standard.
3
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM 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.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
...