Overview
ISO 22605:2020 specifies a laboratory method to determine the dynamic Young’s modulus (MOE) of refractory materials at elevated temperatures using impulse excitation of vibration. The technique measures the specimen’s fundamental resonant frequency in a flexural vibration mode and calculates dynamic MOE from that frequency together with measured mass and geometry. The standard covers slender rectangular bars and cylindrical rods, furnace and transducer requirements, specimen preparation and test procedures (including two measurement methods). NOTE: ISO 22605:2020 does not address safety - users must establish appropriate safety practices.
Key Topics and Requirements
- Specimen types & geometry: slender rectangular parallelepipeds or cylindrical rods; length-to-thickness/diameter ratios specified for valid flexural modes.
- Test principle: excite specimen with a single elastic strike; detect vibrations (microphone, laser vibrometer, etc.); analyse frequency spectrum to obtain fundamental flexural resonant frequency.
- Measurement methods:
- Method A - isothermal measurement after stabilizing at a pre-set test temperature.
- Method B - continuous measurement during slow heating/cooling ramps with repeated impulses.
- Apparatus:
- Furnace providing uniform specimen temperature (±5 °C) and controlled atmosphere (air, inert, or specified gas).
- Impulse excitation tool (adjustable force, non-damaging at test temperature).
- Vibration detector with range (~50 Hz–20 kHz) and frequency analyser accuracy ≤ 0.1%.
- Thermocouple (per IEC 60584‑1/2) near specimen; specimen supports positioned at flexural nodes (0.224 L from ends).
- Specimen handling & accuracy:
- Drying, dimensional measurement (e.g., vernier 0.02 mm) and mass (balance 0.01 g).
- Method is non-destructive but not suitable for specimens with major cracks, voids or irregular geometry - analytical equations assume parallel/concentric dimensions and homogeneity.
Applications and Who Uses It
- Applications:
- Characterization of refractory materials’ elastic properties at elevated temperatures.
- Quality control and production testing of shaped and unshaped refractories.
- R&D and materials development (comparing formulations, sintering effects, thermal conditioning).
- Typical users:
- Refractory manufacturers, materials and ceramic test laboratories, metallurgical and furnace engineers, quality managers, and research organizations working with high-temperature linings and insulation.
Related Standards
- ISO 12680-1 - MOE by impulse excitation at room temperature
- ISO 5022, ISO 8656-1 - sampling for shaped/unshaped refractory products
- ISO 16835 - thermal expansion of refractories
- IEC 60584-1 / IEC 60584-2 - thermocouple EMF specifications and tolerances
Keywords: ISO 22605:2020, refractories, dynamic Young’s modulus, MOE, impulse excitation, resonant frequency, flexural vibration, high-temperature testing, non-destructive testing.