Overview
ISO 17140:2014 - Fine ceramics (advanced ceramics, advanced technical ceramics) - specifies procedures for determining fatigue properties at constant amplitude of load or strain for ceramic matrix composites (CMCs) with fibre reinforcement at room temperature. It covers uniaxial cyclic fatigue in tension/tension and tension/compression modes and applies to unidirectional (1D), bidirectional (2D) and tri-/multi-directional (xD) fibre architectures.
Key topics and technical requirements
- Test principle: Two main methods - load-controlled (Method A) and strain-controlled (Method B) constant-amplitude cyclic testing. Total number of cycles and time-to-failure are recorded; strain monitoring enables additional damage metrics.
- Fatigue parameters & nomenclature: Definitions of load ratio (R), maximum/minimum/mean stress (σmax, σmin, σm), stress/strain amplitude (σa, εa), number of cycles (N, Nf), and time to failure (tf).
- Apparatus requirements:
- Hydraulic or electric actuator test machine with load or strain control.
- Force measurement system conforming to ISO 7500-1 (grade 1 or better).
- Extensometer compatible with chosen frequency, conforming to ISO 9513 (class 1 or better) for continuous longitudinal deformation measurement.
- Calibrated data recording system (digital recommended) and micrometers per ISO 3611 for specimen dimensions.
- Load train and fixturing: Alignment of specimen and load cell, grips that prevent slipping (hydraulic grips recommended).
- Specimen design & preparation: Geometry chosen to ensure failure in the gauge length; machining, number of specimens and dimensional measurement guidance included.
- Measured outputs: Lifetime (S–N/ε–N style diagrams), residual properties, damage evolution metrics (residual strain, secant modulus, hysteresis loop area), and criteria for test validity.
- Reporting & calculations: Procedures to compute time-to-failure, damage parameters, residual mechanical properties and required test report content.
Practical applications and users
ISO 17140:2014 is used to:
- Characterize cyclic fatigue behaviour of CMC materials for component qualification.
- Develop lifetime diagrams and fatigue limits for design and safety margins.
- Support R&D and material selection in high-temperature structural applications (aerospace, gas turbines, energy, automotive, defense).
- Provide standardized test protocols in materials testing laboratories, certification bodies and academic research.
Typical users include materials engineers, fatigue test laboratories, product qualification teams, and researchers working with advanced ceramics and ceramic matrix composites.
Related standards
Normative references incorporated in ISO 17140:2014 include:
For full implementation details and mandatory clauses, consult the complete ISO 17140:2014 standard.