Overview
ISO 21713:2020 specifies a high-temperature test method for determining the elastic modulus (Young’s modulus) of fine ceramics using the thin‑wall relative C‑ring method. The standard covers tests up to 2 100 °C, including procedures for test‑piece preparation, test modes, heating and loading rates, data acquisition and reporting. It is intended for monolithic fine ceramics, refractory materials and whisker/particulate‑reinforced ceramic composites, but is not applicable to superplastic ceramics or ceramics with high creep rates.
Key topics and technical requirements
- Test principle: Use of a split thin‑wall C‑ring and a rigid disk of identical outer dimensions. At high temperatures the real deformation of the C‑ring is obtained by subtracting the machine/system displacement (measured with the rigid disk) from the total crossbeam displacement.
- Temperature range: Measurements up to 2100 °C with controlled heating and thermal equilibrium prior to loading.
- Furnace and thermal control:
- Temperature stability: typically ±2 °C or better within the working space while loaded.
- Uniformity: test piece temperature variation ≤ 10 °C after a 15 min hold.
- Heating rate control and prevention of overshoot; determination of thermal equilibrium time.
- Instrumentation:
- Thermocouples in accordance with IEC 60584‑1, low thermal inertia (≤ 0.5 mm wire diameter), checked periodically.
- Testing machine force measurement meeting ISO 7500‑1 accuracy requirements (≤1% measuring accuracy).
- Data acquisition: minimum 10 Hz sampling (50 Hz recommended), record load vs. crosshead displacement or time.
- Dimension measuring: resolution 0.01 mm (ISO 3611).
- Test pieces: Geometry constraints for thin‑wall assumptions (e.g., ratio r/R between specified limits); preparation and storage requirements; use of rigid disk for system error compensation.
- Results: Elastic modulus calculated from load–deformation curves and test‑piece dimensions; reporting of mean and standard deviation.
Applications
- Material research and high‑temperature characterization of advanced ceramics.
- Quality control and acceptance testing for ceramic components and refractory materials.
- Generation of design data for engineers working on high‑temperature components (thermal barriers, furnace linings, structural ceramics).
- Comparative material screening for composites (whisker/particulate reinforced).
Who should use ISO 21713:2020
- Materials scientists and research laboratories performing mechanical property evaluation at elevated temperatures.
- Industrial test laboratories and manufacturers of advanced ceramics and refractories.
- Design engineers requiring validated high‑temperature elastic modulus data for simulations and component design.
- Quality managers implementing standardized test methods for production control.
Related standards
- ISO 7500‑1 - Calibration and verification of static uniaxial testing machines.
- IEC 60584‑1 - Thermocouples: reference tables.
- ISO 3611 - Micrometers for external measurements (dimension‑measuring precision).
Keywords: ISO 21713:2020, elastic modulus, fine ceramics, C‑ring method, high temperature testing, thin wall C‑ring, Young’s modulus, ceramic testing, thermocouples, furnace stability.
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