Overview
ISO 18142:2014 specifies a laboratory method to determine the dynamic modulus of elasticity of solid carbonaceous and graphite specimens (baked carbon bodies) used in the production of primary aluminium. The standard uses the resonance method at room temperature: a rod-shaped specimen is excited to longitudinal oscillation, the fundamental resonance frequency is measured, and the dynamic elasticity modulus is calculated from the resulting sound velocity and the specimen’s apparent density.
Keywords: ISO 18142:2014, dynamic modulus of elasticity, resonance method, baked carbon bodies, carbonaceous materials, primary aluminium, resonance frequency, sound velocity.
Key Topics
- Scope and principle
- Applies to solid carbonaceous or graphite specimens at room temperature.
- Dynamic modulus derived from sound velocity obtained from the specimen’s fundamental resonance frequency.
- Based on DIN 51915 methodology.
- Specimen requirements
- Rod-shaped specimens with uniform cross section (circular or rectangular preferred).
- Length at least three times the largest cross-sectional dimension; end faces perpendicular to axis.
- Minimum dimensions related to largest particle size to avoid heterogeneity effects.
- Apparatus and setup
- Frequency generator/receiver, vibration generator, vibration pickup, supports and measuring instruments (callipers/micrometers).
- Specimen supported at quarter-length nodes to allow undisturbed fundamental vibration.
- Probes contact specimen near mid-face with low contact force (adjustable counterweight suggested).
- Calculations and evaluation
- Sound velocity obtained from measured resonance frequency and specimen length.
- Dynamic modulus calculated from sound velocity and apparent density following the formulas provided in the standard.
- Precision
- Repeatability and reproducibility limits are specified (e.g., for 1–10 GPa: repeatability 0.1 GPa, reproducibility 0.2 GPa; over 10 GPa: 0.2 GPa and 0.4 GPa respectively).
- Sampling and reporting
- Sampling in accordance with ISO 8007 series unless otherwise agreed.
- Test report must include reference to ISO 18142:2014, specimen details, individual and mean E_dyn values, and any deviations.
Applications
- Quality control and acceptance testing of baked carbon anodes, cathode blocks and sidewall blocks used in aluminium smelting.
- Materials characterization in R&D labs evaluating thermal shock resistance and elastic deformation behavior of carbonaceous products.
- Supplier verification tests and cross-laboratory comparisons for procurement and production control.
Related Standards
This summary helps engineers, laboratory managers and materials specialists locate and apply ISO 18142:2014 for reliable dynamic elasticity testing of carbonaceous materials used in primary aluminium production.