ASTM C1273
Tensile Fixture for Monolithic Advanced Ceramics
ASTM C1273 Ceramic Tensile Fixture – Universal Grip Data Sheet (PDF)
ASTM C1273 measures the uniaxial tensile strength of monolithic advanced ceramics at room temperature. Materials developers and designers use it when they need true tensile strength data rather than flexural results. Universal Grip supplies an aligned tensile fixture with grip inserts matched to shouldered or flat ceramic specimens.
What ASTM C1273 Measures
The test reports the tensile strength of a ceramic specimen loaded in monotonic uniaxial tension, along with failure location and mode. A tensile test stresses a larger volume of material uniformly than a bend test, so it better samples the flaws that limit strength in real parts. Because ceramic strength varies with flaw population and specimen size, the standard calls for enough specimens for statistical analysis, and results can be scaled to effective volume or surface using ASTM C1239.
How the ASTM C1273 Test Works
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Verify load train alignment, typically with a strain-gauged alignment specimen.
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Install the specimen in grip inserts matched to its shoulders or faces.
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Apply a small preload and confirm the specimen is seated without added bending.
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Load in force, displacement or strain control at the selected rate until fracture.
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Record fracture load and location; only gauge-section failures are typically valid.
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Calculate tensile strength and, for design data, examine fracture surfaces to find the origin.
Specimens and Setup
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Shouldered (dogbone) or flat specimens are used, with geometry chosen to put failure in the uniform gauge section.
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Specimen machining has a strong effect on results; follow a consistent, documented procedure.
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Bending must be kept low, so alignment is checked before testing and after any change to the load train.
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Test enough specimens for statistical analysis; the standard gives guidance on minimum numbers.
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Send us your specimen drawing so grip inserts can be matched to its shoulders or faces.
Universal Grip ASTM C1273 Fixture
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Load train designed for low-bending alignment; alignment couplers available
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Grip inserts matched to shouldered or flat specimen geometries
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Compliant interfaces reduce stress concentrations at the grip
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Compatible with strain-gauged alignment verification specimens
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Heat-treated alloy steel, 10 kN (about 2,250 lbf) standard capacity, higher on request
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Clevis pin or threaded adapter for electromechanical and servo-hydraulic test machines
Applications
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Silicon nitride and silicon carbide
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Alumina and zirconia ceramics
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Design allowables for ceramic parts
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Materials research and qualification
Related Standards and Products
Send your specimen drawing, required capacity and machine connection through our contact page for a quote on an ASTM C1273 ceramic tensile fixture. Request a quote
ASTM C1273 FAQ
Why is alignment so important in ceramic tensile testing?
Ceramics are brittle and cannot yield to relieve uneven stress. Even small misalignment adds bending, raising stress on one side of the gauge section and lowering the measured strength. That is why C1273 sets limits on allowable bending and the load train is verified before testing.
Why run a tensile test instead of a flexure test?
Flexure tests put peak stress on a small region near the surface, while a tensile test stresses the whole gauge volume uniformly. Tensile data better reflect volume-distributed flaws and are often preferred for design, though they require more careful specimen preparation and alignment.
How is alignment verified?
A specimen fitted with strain gauges around the gauge section is loaded, and the strain differences are used to calculate percent bending. The fixture is compatible with these verification specimens, and alignment couplers can be added to correct offset and angularity.
How are results reported?
Each test gives tensile strength from fracture load and gauge cross-section, plus failure location. Sets are summarized with mean and scatter, often with Weibull statistics, and fractography is strongly recommended to identify the flaw that started each fracture.
What machine capacity do I need?
Ceramic tensile specimens are usually small, so the standard fixture is rated at 10 kN (about 2,250 lbf). Your frame and load cell should be sized to the expected fracture load with good resolution. Higher-capacity fixtures are available for larger or stronger specimens.