ISO 17562:2016

Overview

ISO 17562:2016 defines a standardized test method for measuring the linear thermal expansion and the linear thermal expansion coefficient of monolithic fine ceramics (advanced/technical ceramics) using the push‑rod (dilatometer) technique. The method covers a wide temperature range-from near liquid nitrogen temperature up to a maximum of 2000 °C-and specifies the principles, apparatus, specimen preparation, measurement procedure, calibration and reporting required to produce reliable, comparable CTE data.

Key topics and technical requirements

• Measurement principle: Record specimen length change versus temperature under controlled heating/cooling and minimal mechanical load; calculate mean and instantaneous linear thermal expansion coefficients.
• Temperature range & control: Applicable from cryogenic (near liquid nitrogen) to 2000 °C. Temperature control should enable controlled rates (typically ≤ 5 °C/min) or step changes; homogeneity requirements are tighter below 1000 °C (±2 °C) and relaxed above (±5 °C up to 2000 °C).
• Apparatus: Use a push‑rod dilatometer (single‑rod or differential) with:
  • Displacement measurement capability with high sensitivity (device selection matched to specimen length).
  • Adjustable push‑rod contact force typically 0.1 N to 1 N.
  • Temperature measurement (thermocouple) with uncertainty < 2 °C and tip close to specimen.
• Specimens: Monolithic rod specimens (circular or square cross‑section), typical cross‑section ~5 mm; length sufficient relative to instrument sensitivity; prepare at least two specimens.
• Reference specimen & baseline: Use a reference material with known expansion (e.g., high‑purity alumina or fine‑grained isotropic graphite) similar in size to the test specimen to calibrate and correct measured data.
• Procedure: Clean specimens, mount to ensure stability, apply minimal contact force, run at least two thermal cycles without removing specimen, record continuous length and temperature data.
• Atmosphere: Air is standard; use inert gas or vacuum if oxidation affects results. Note safety/chemical cautions (e.g., nitrogen with graphite at very high temperatures).
• Calibration & uncertainty: Clause details for displacement and temperature calibration, baseline variation measurement and expected uncertainty levels.

Applications and users

ISO 17562:2016 is used by:

• Materials scientists and ceramic engineers characterizing coefficient of thermal expansion (CTE).
• R&D and quality control laboratories validating thermal properties of fine ceramics.
• Manufacturers of ceramic components for aerospace, electronics, optics, refractories and high‑temperature engines where CTE matching and thermal shock resistance are critical.
• Dilatometer and furnace equipment manufacturers for device validation and calibration. Practical uses include CTE data for component design, thermal stress analysis, composite design, and material selection for multi‑material assemblies.

Related standards

• ISO 17139 (thermophysical properties of ceramic composites)
• ISO 7991 (glass thermal expansion)
• IEC 60584 (thermocouple reference/tolerances)
• BS 1902-5.14 (refractory thermal expansion methods)

Keywords: ISO 17562:2016, linear thermal expansion, push-rod technique, dilatometer, monolithic ceramics, fine ceramics, thermal expansion coefficient, CTE testing.