Overview
EN ISO 17139:2022 (ISO 17139:2014) specifies standardized methods for determining the linear thermal expansion of ceramic matrix composite materials (fine ceramics / advanced ceramics) up to 2 300 K. Adopted by CEN as EN ISO 17139:2022, the standard covers construction, calibration and operation principles for apparatus used to measure thermophysical properties - especially the coefficient of thermal expansion (CTE) - of 1D, 2D and nD ceramic composites.
Key topics and technical requirements
- Scope and principles
- Measurement of length change during controlled heating and cooling cycles; continuous or frequent interval recording.
- Two permitted methods: direct measurement (measuring test-piece displacement vs. calibrated support system) and differential method (measuring length change between a reference piece and test piece).
- Temperature range and atmosphere
- Applicable to temperatures up to 2 300 K.
- For temperatures above 1 400 °C, use vacuum or inert gas atmosphere and non-oxide materials (e.g., dense graphite) when appropriate.
- For temperatures beyond ~2 000 K, infrared detectors or suitable high-temperature sensors may be used.
- Instrumentation and accuracy
- Furnace control to within 1% of mean temperature (in K).
- Thermocouples per IEC 60584-1; tungsten–rhenium couples may be used at higher temperatures (not covered by IEC 60584-1) and should be calibrated individually.
- Displacement measurement accuracy better than 0.1 μm; dimensional measurement accuracy better than 0.05 mm.
- Periodic calibration required (Annex A for direct, Annex B for differential).
- Specimen mounting
- Holders and push rods must be thermomechanically stable, chemically inert and thermally compatible with test material.
- Mounts must allow free axial movement, minimize stresses and restrict lateral motion without constraining axial expansion.
Applications and users
EN ISO 17139:2022 is intended for:
- Materials testing and dilatometry labs performing CTE characterization of ceramic matrix composites.
- R&D teams and quality control in advanced ceramics, aerospace, power generation, electronics and high-temperature component manufacturers.
- Engineers and designers who need validated thermal expansion data for thermal stress analysis, component design and lifetime prediction.
- Accredited testing laboratories seeking compliance with normative references such as ISO/IEC 17025.
Practical applications include qualification of ceramic composites for thermal cycling, matching CTEs in multi-material assemblies, and supplying certified thermophysical data for simulation and specification.
Related standards
Keywords: EN ISO 17139:2022, ISO 17139:2014, thermal expansion, ceramic composites, fine ceramics, coefficient of thermal expansion, CTE, dilatometry, thermophysical properties, advanced ceramics.
