C28.04 - Applications

SIGNIFICANCE AND USE
5.1 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 mm or greater.  
5.2 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.  
5.3 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.  
5.4 Test Method A is a user-defined specimen geometry with a choice of four-point or three-point flexure testing geometries. It is not possible to define a single fixed specimen geometry for flexure testing of honeycombs, because of the wide range of honeycomb architectures and cell sizes and consid...
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 mm or greater. Ceramics with these honeycomb structures are used in a wide range of applications (catalytic conversion supports (1),2 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 compositions—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).
FIG. 1 General Schematics of Typical Honeycomb Ceramic Structures  
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):
FIG. 2 Flexure Loading Configurations  
L = Outer Span Length (for Test Method A, L = User defined; for Test Method B, L = 90 mm)
Note 1: 4-Point-1/4 Loading for Test Methods A1 and B.
Note 2: 3-Point Loading for Test Method A2.  
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-1/4 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 loa...

SIGNIFICANCE AND USE
5.1 This test is intended to assess the mechanical integrity, failure modes, and practical adhesion strength of a specific hard ceramic coating on a given metal or ceramic substrate. The test method does not measure the fundamental “adhesion strength” of the bond between the coating and the substrate. Rather, the test method gives a quantitative engineering measurement of the practical (extrinsic) adhesion strength and damage resistance of the coating-substrate system as a function of applied normal force. The adhesion strength and damage modes depend on the complex interaction of the coating-substrate properties (hardness, fracture strength, modulus of elasticity, damage mechanisms, microstructure, flaw population, surface roughness, and so forth) and the test parameters (stylus properties and geometry, loading rate, displacement rate, and so forth).  
5.2 The test method as described herein is not appropriate for polymer coatings, ductile metal coatings, very thin (30 μm) ceramic coatings.
Note 2: Under narrow circumstances, the test may be used for ceramic coatings on polymer substrates with due consideration of the differences in elastic modulus, ductility, and strength between the two types of materials. Commonly, the low comparative modulus of the polymer substrate means that the ceramic coating will generally tend to fail in bending (through-thickness adhesive failure) before cohesive failure in the coating itself.  
5.3 The quantitative coating adhesion scratch test is a simple, practical, and rapid test. However, reliable and reproducible test results require careful control of the test system configuration and testing parameters, detailed analysis of the coating damage features, and appropriate characterization of the properties and morphology of the coating and the substrate of the test specimens.  
5.4 The coating adhesion test has direct application across the full range of coating development, engineering, and production efforts. Measurements of t...
SCOPE
1.1 This test method covers the determination of the practical adhesion strength and mechanical failure modes of hard (Vickers Hardness HV = 5 GPa or higher), thin (≤30 μm) ceramic coatings on metal and ceramic substrates at ambient temperatures. These ceramic coatings are commonly used for wear/abrasion resistance, oxidation protection, and functional (optical, magnetic, electronic, biological) performance improvement.  
1.2 In the test method, a diamond stylus of defined geometry (Rockwell C, a conical diamond indenter with an included angle of 120° and a spherical tip radius of 200 μm) is drawn across the flat surface of a coated test specimen at a constant speed and a defined normal force (constant or progressively increasing) for a defined distance. The damage along the scratch track is microscopically assessed as a function of the applied force. Specific levels of progressive damage are associated with increasing normal stylus forces. The force level(s) which produce a specific type/level of damage in the coating are defined as a critical scratch load(s). The test method also describes the use of tangential force and acoustic emission signals as secondary test data to identify different coating damage levels.  
1.3 Applicability to Coatings—This test method is applicable to a wide range of hard ceramic coating compositions: carbides, nitrides, oxides, diamond, and diamond-like carbon on ceramic and metal substrates. The test method, as defined with the 200 μm radius diamond stylus, is commonly used for coating thicknesses in the range of 0.1 to 30 μm. Test specimens generally have a planar surface for testing, but cylinder geometries can also be tested with an appropriate fixture.  
1.4 Principal Limitations:  
1.4.1 The test method does not measure the fundamental adhesion strength of the bond between the coating and the substrate. Rather, the test method gives an engineering measurement of the practical (ext...

SIGNIFICANCE AND USE
4.1 This test method may be used for material development, material comparison, quality assurance, and characterization. Extreme care should be exercised when generating design data.  
4.2 For a C-ring under diametral compression, the maximum tensile stress occurs at the outer surface. Hence, the C-ring specimen loaded in compression will predominately evaluate the strength distribution and flaw population(s) on the external surface of a tubular component in the hoop direction. Accordingly, the condition of the inner surface may be of lesser consequence in specimen preparation and testing.
Note 1: A C-ring in tension or an O-ring in compression may be used to evaluate the internal surface.  
4.2.1 The flexure stress is computed based on simple curved beam theory (1-5).3 It is assumed that the material is isotropic and homogeneous, the moduli of elasticity are identical in compression or tension, and the material is linearly elastic. These homogeneity and isotropy assumptions preclude the use of this standard for continuous fiber reinforced composites. Average grain size(s) should be no greater than one fiftieth (1/50 ) of the C-ring thickness. The curved beam stress solution from engineering mechanics is in good agreement (within 2 %) with an elasticity solution as discussed in (6) for the test specimen geometries recommended for this standard. The curved beam stress equations are simple and straightforward, and therefore it is relatively easy to integrate the equations for calculations for effective area or effective volume for Weibull analyses as discussed in Appendix X1.  
4.2.2 The simple curved beam and theory of elasticity stress solutions both are two-dimensional plane stress solutions. They do not account for stresses in the axial (parallel to b) direction, or variations in the circumferential (hoop, σθ) stresses through the width (b) of the test piece. The variations in the circumferential stresses increase with increases in width (b) and ring thicknes...
SCOPE
1.1 This test method covers the determination of ultimate strength under monotonic loading of advanced ceramics in tubular form at ambient temperatures. The ultimate strength as used in this test method refers to the strength obtained under monotonic compressive loading of C-ring specimens such as shown in Fig. 1, where monotonic refers to a continuous nonstop test rate with no reversals from test initiation to final fracture. This method permits a range of sizes and shapes since test specimens may be prepared from a variety of tubular structures. The method may be used with microminiature test specimens.
FIG. 1 C-Ring Test Geometry with Defining Geometry and Reference Angle (θ) for the Point of Fracture Initiation on the Circumference  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.2.1 Values expressed in this test method are in accordance with the International System of Units (SI) and IEEE/ASTM SI 10.  
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.

SIGNIFICANCE AND USE
5.1 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 mm or greater.  
5.2 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.  
5.3 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.  
5.4 Test Method A is a user-defined specimen geometry with a choice of four-point or three-point flexure testing geometries. It is not possible to define a single fixed specimen geometry for flexure testing of honeycombs, because of the wide range of honeycomb architectures and cell sizes and consid...
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 mm or greater. Ceramics with these honeycomb structures are used in a wide range of applications (catalytic conversion supports (1),2 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 compositions—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).  
L = Outer Span Length (for Test Method A, L = User defined; for Test Method B, L = 90 mm)
Note 1: 4-Point-1/4 Loading for Test Methods A1 and B.
Note 2: 3-Point Loading for Test Method A2.  
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-1/4 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 specifi...

SIGNIFICANCE AND USE
4.1 This test method may be used for material development, material comparison, quality assurance, and characterization. Extreme care should be exercised when generating design data.  
4.2 For a C-ring under diametral compression, the maximum tensile stress occurs at the outer surface. Hence, the C-ring specimen loaded in compression will predominately evaluate the strength distribution and flaw population(s) on the external surface of a tubular component. Accordingly, the condition of the inner surface may be of lesser consequence in specimen preparation and testing.
Note 1: A C-ring in tension or an O-ring in compression may be used to evaluate the internal surface.  
4.2.1 The flexure stress is computed based on simple curved-beam theory (1, 2, 3, 4, 5).3 It is assumed that the material is isotropic and homogeneous, the moduli of elasticity are identical in compression or tension, and the material is linearly elastic. These homogeneity and isotropy assumptions preclude the use of this standard for continuous fiber reinforced composites. Average grain size(s) should be no greater than one fiftieth (1/50 ) of the C-ring thickness. The curved-beam stress solution from engineering mechanics is in good agreement (within 2 %) with an elasticity solution as discussed in (6) for the test specimen geometries recommended for this standard. The curved beam stress equations are simple and straightforward, and therefore it is relatively easy to integrate the equations for calculations for effective area or effective volume for Weibull analyses as discussed in Appendix X1.  
4.2.2 The simple curved beam and theory of elasticity stress solutions both are two-dimensional plane stress solutions. They do not account for stresses in the axial (parallel to b) direction, or variations in the circumferential (hoop, σθ) stresses through the width (b) of the test piece. The variations in the circumferential stresses increase with increases in width (b) and ring thickness (t). The v...
SCOPE
1.1 This test method covers the determination of ultimate strength under monotonic loading of advanced ceramics in tubular form at ambient temperatures. The ultimate strength as used in this test method refers to the strength obtained under monotonic compressive loading of C-ring specimens such as shown in Fig. 1 where monotonic refers to a continuous nonstop test rate with no reversals from test initiation to final fracture. This method permits a range of sizes and shapes since test specimens may be prepared from a variety of tubular structures. The method may be used with microminiature test specimens.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.2.1 Values expressed in this test method are in accordance with the International System of Units (SI) and IEEE/ASTM SI 10.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This test is intended to assess the mechanical integrity, failure modes, and practical adhesion strength of a specific hard ceramic coating on a given metal or ceramic substrate. The test method does not measure the fundamental “adhesion strength” of the bond between the coating and the substrate. Rather, the test method gives a quantitative engineering measurement of the practical (extrinsic) adhesion strength and damage resistance of the coating-substrate system as a function of applied normal force. The adhesion strength and damage modes depend on the complex interaction of the coating/substrate properties (hardness, fracture strength, modulus of elasticity, damage mechanisms, microstructure, flaw population, surface roughness, and so forth) and the test parameters (stylus properties and geometry, loading rate, displacement rate, and so forth).  
5.2 The quantitative coating adhesion scratch test is a simple, practical, and rapid test. However, reliable and reproducible test results require careful control of the test system configuration and testing parameters, detailed analysis of the coating damage features, and appropriate characterization of the properties and morphology of the coating and the substrate of the test specimens.  
5.3 The coating adhesion test has direct application across the full range of coating development, engineering, and production efforts. Measurements of the damage mechanisms in a coating as a function of applied normal forces are useful to understand material-process-property relations; quantify and qualify the mechanical response of coating-substrate systems; assess coating durability; measure production quality; and support failure analysis.  
5.4 This test method is applicable to a wide range of hard ceramic coating compositions—carbides, nitrides, oxides, diamond, and diamond like carbon—applied by physical vapor deposition, chemical vapor deposition, and direct oxidation methods to metal and ceramic substrates.
Note 2: U...
SCOPE
1.1 This test method covers the determination of the practical adhesion strength and mechanical failure modes of hard (Vickers Hardness HV = 5 GPa or higher), thin (≤30 μm) ceramic coatings on metal and ceramic substrates at ambient temperatures. These ceramic coatings are commonly used for wear/abrasion resistance, oxidation protection, and functional (optical, magnetic, electronic, biological) performance improvement.  
1.2 In the test method, a diamond stylus of defined geometry (Rockwell C, a conical diamond indenter with an included angle of 120° and a spherical tip radius of 200 μm) is drawn across the flat surface of a coated test specimen at a constant speed and a defined normal force (constant or progressively increasing) for a defined distance. The damage along the scratch track is microscopically assessed as a function of the applied force. Specific levels of progressive damage are associated with increasing normal stylus forces. The force level(s) which produce a specific type/level of damage in the coating are defined as a critical scratch load(s). The test method also describes the use of tangential force and acoustic emission signals as secondary test data to identify different coating damage levels.  
1.3 Applicability to Coatings—This test method is applicable to a wide range of hard ceramic coating compositions: carbides, nitrides, oxides, diamond, and diamond-like carbon on ceramic and metal substrates. The test method, as defined with the 200 μm radius diamond stylus, is commonly used for coating thicknesses in the range of 0.1 to 30 μm. Test specimens generally have a planar surface for testing, but cylinder geometries can also be tested with an appropriate fixture.  
1.4 Principal Limitations:  
1.4.1 The test method does not measure the fundamental adhesion strength of the bond between the coating and the substrate. Rather, the test method gives an engineering measurement of the practical (extr...

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.

SIGNIFICANCE AND USE
This test is intended to assess the mechanical integrity, failure modes, and practical adhesion strength of a specific hard ceramic coating on a given metal or ceramic substrate. The test method does not measure the fundamental “adhesion strength” of the bond between the coating and the substrate. Rather, the test method gives a quantitative engineering measurement of the practical (extrinsic) adhesion strength and damage resistance of the coating-substrate system as a function of applied normal force. The adhesion strength and damage modes depend on the complex interaction of the coating/substrate properties (hardness, fracture strength, modulus of elasticity, damage mechanisms, microstructure, flaw population, surface roughness, and so forth) and the test parameters (stylus properties and geometry, loading rate, displacement rate, and so forth).
The quantitative coating adhesion scratch test is a simple, practical, and rapid test. However, reliable and reproducible test results require careful control of the test system configuration and testing parameters, detailed analysis of the coating damage features, and appropriate characterization of the properties and morphology of the coating and the substrate of the test specimens.
The coating adhesion test has direct application across the full range of coating development, engineering, and production efforts. Measurements of the damage mechanisms in a coating as a function of applied normal forces are useful to understand material-process-property relations; quantify and qualify the mechanical response of coating-substrate systems; assess coating durability; measure production quality; and support failure analysis.
This test method is applicable to a wide range of hard ceramic coating compositionscarbides, nitrides, oxides, diamond, and diamond like carbonapplied by physical vapor deposition, chemical vapor deposition, and direct oxidation methods to metal and ceramic substrates.
Note 2—Under narrow circumsta...
SCOPE
1.1 This test method covers the determination of the practical adhesion strength and mechanical failure modes of hard (Vickers Hardness HV = 5 GPa or higher), thin (≤30 μm) ceramic coatings on metal and ceramic substrates at ambient temperatures. These ceramic coatings are commonly used for wear/abrasion resistance, oxidation protection, and functional (optical, magnetic, electronic, biological) performance improvement.
1.2 In the test method, a diamond stylus of defined geometry (Rockwell C, a conical diamond indenter with an included angle of 120° and a spherical tip radius of 200 μm) is drawn across the flat surface of a coated test specimen at a constant speed and a defined normal force (constant or progressively increasing) for a defined distance. The damage along the scratch track is microscopically assessed as a function of the applied force. Specific levels of progressive damage are associated with increasing normal stylus forces. The force level(s) which produce a specific type/level of damage in the coating are defined as a critical scratch load(s). The test method also describes the use of tangential force and acoustic emission signals as secondary test data to identify different coating damage levels.
1.3 Applicability to Coatings—This test method is applicable to a wide range of hard ceramic coating compositions: carbides, nitrides, oxides, diamond, and diamond-like carbon on ceramic and metal substrates. The test method, as defined with the 200 μm radius diamond stylus, is commonly used for coating thicknesses in the range of 0.1 to 30 μm. Test specimens generally have a planar surface for testing, but cylinder geometries can also be tested with an appropriate fixture.
1.4 Principal Limitations:
1.4.1 The test method does not measure the fundamental adhesion strength of the bond between the coating and the substrate. Rather, the test method gives an engineering measurement of the practical (extri...

SIGNIFICANCE AND USE
This test method may be used for material development, material comparison, quality assurance, and characterization. Extreme care should be exercised when generating design data.  
For a C-ring under diametral compression, the maximum tensile stress occurs at the outer surface. Hence, the C-ring specimen loaded in compression will predominately evaluate the strength distribution and flaw population(s) on the external surface of a tubular component. Accordingly, the condition of the inner surface may be of lesser consequence in specimen preparation and testing.  
Note 1—A C-ring in tension or an O-ring in compression may be used to evaluate the internal surface.  
The flexure stress is computed based on simple curved-beam theory (1, 2, 3, 4, 5). It is assumed that the material is isotropic and homogeneous, the moduli of elasticity are identical in compression or tension, and the material is linearly elastic. These homogeneity and isotropy assumptions preclude the use of this standard for continuous fiber reinforced composites. Average grain size(s) should be no greater than one fiftieth (1/50) of the C-ring thickness. The simple curved-beam theory stress solution is in good agreement (typically better than 1%) with a theory of elasticity solution as discussed in (3) for the geometries chosen for this standard. The simple beam theory stress equations are relatively simple. They are relatively easy to integrate for Weibull effective volume or effective area computations as shown in Appendix X1.
The simple curved beam and theory of elasticity stress solutions both are two-dimensional plane stress solutions. They do not account for stresses in the axial (parallel to b) direction, or variations in the circumferential (hoop, σθ) stresses through the width (b) of the test piece. The variations in the circumferential stresses increase with increases in width (b) and ring thickness (t). The variations can be substantial (> 10 %) for test specimens with large b. The circ...
SCOPE
1.1 This test method covers the determination of ultimate strength under monotonic loading of advanced ceramics in tubular form at ambient temperatures. The ultimate strength as used in this test method refers to the strength obtained under monotonic compressive loading of C-ring specimens such as shown in Fig. 1 where monotonic refers to a continuous nonstop test rate with no reversals from test initiation to final fracture. This method permits a range of sizes and shapes since test specimens may be prepared from a variety of tubular structures. The method may be used with microminiature test specimens.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.2.1 Values expressed in this test method are in accordance with the International System of Units (SI) and .
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 and health practices and determine the applicability of regulatory limitations prior to use.

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.
Test Method A is a user-defined specimen geometry with a choice of four-point or three-point flexure testing geometries. It is not possible to define a single fixed specimen geometry for flexure testing of honeycombs, because of the wide range of honeycomb architectures and cell sizes and considerations o...
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 compositions—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
1.3.2 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 T...

SCOPE
1.1 This test method covers the determination of the practical adhesion strength and mechanical failure modes of hard (Vickers Hardness HV = 5 GPa or higher), thin (≤30 μm) ceramic coatings on metal and ceramic substrates at ambient temperatures. These ceramic coatings are commonly used for wear/abrasion resistance, oxidation protection, and functional (optical, magnetic, electronic, biological) performance improvement.
1.2 In the test method, a diamond stylus of defined geometry (Rockwell C, a conical diamond indenter with an included angle of 120° and a spherical tip radius of 200 μm) is drawn across the flat surface of a coated test specimen at a constant speed and a defined normal force (constant or progressively increasing) for a defined distance. The damage along the scratch track is microscopically assessed as a function of the applied force. Specific levels of progressive damage are associated with increasing normal stylus forces. The force level(s) which produce a specific type/level of damage in the coating are defined as a critical scratch load(s). The test method also describes the use of tangential force and acoustic emission signals as secondary test data to identify different coating damage levels.
1.3 Applicability to Coatings—This test method is applicable to a wide range of hard ceramic coating compositions: carbides, nitrides, oxides, diamond, and diamond-like carbon on ceramic and metal substrates. The test method, as defined with the 200 μm radius diamond stylus, is commonly used for coating thicknesses in the range of 0.1 to 30 μm. Test specimens generally have a planar surface for testing, but cylinder geometries can also be tested with an appropriate fixture.
1.4 Principal Limitations:
1.4.1 The test method does not measure the fundamental adhesion strength of the bond between the coating and the substrate. Rather, the test method gives an engineering measurement of the practical (extrinsic) adhesion strength of a coating-substrate system, which depends on the complex interaction of the test parameters (stylus properties and geometry, loading rate, displacement rate, and so forth) and the coating/substrate properties (hardness, fracture strength, modulus of elasticity, damage mechanisms, microstructure, flaw population, surface roughness, and so forth).
1.4.2 The defined test method is not directly applicable to metal or polymeric coatings which fail in a ductile, plastic manner, because plastic deformation mechanisms are very different than the brittle damage modes and features observed in hard ceramic coatings. The test method may be applicable to hard metal coatings which fail in a brittle mode with appropriate changes in test parameters and damage analysis procedures and criteria.
1.4.3 The test method, as defined with the Rockwell C diamond stylus and specific normal force and rate parameters, is not recommended for very thin (30 μm). Such coatings may require different stylus geometries, loading rates, and ranges of applied normal force for usable, accurate, repeatable results.
1.4.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Test data values in SI units (newtons (N) for force and millimetres (mm) for displacement) are to be considered as standard and are in accordance with IEEE/ASTM SI 10.
1.4.5 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.

SCOPE
1.1 This test method covers the determination of ultimate strength under monotonic loading of advanced ceramics in tubular form at ambient temperatures. Note that ultimate strength as used in this test method refers to the strength obtained under monotonic compressive loading of C-ring specimens where monotonic refers to a continuous nonstop test rate with no reversals from test initiation to final fracture.
1.2 Values expressed in this test method are in accordance with the International System of Units (SI) and Practice E 380.
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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of ultimate strength under monotonic loading of advanced ceramics in tubular form at ambient temperatures. Note that ultimate strength as used in this test method refers to the strength obtained under monotonic compressive loading of C-ring specimens where monotonic refers to a continuous nonstop test rate with no reversals from test initiation to final fracture.  
1.2 Values expressed in this test method are in accordance with the International System of Units (SI) and Practice E380.  
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 and health practices and determine the applicability of regulatory limitations prior to use.