Overview
ISO 19634:2017 - Fine ceramics (advanced ceramics, advanced technical ceramics) - Ceramic composites - Notations and symbols defines a standardized system of notations and symbols for reporting the physical, mechanical and thermal characteristics of ceramic matrix composites (CMCs). The standard aims to avoid ambiguity when publishing measurement results and product data by specifying symbols, nomenclature and the meaning and use of those symbols. Where possible, definitions align with the relevant parts of ISO 80000.
Key topics
- Scope and purpose: Symbols to represent density, porosity, phase volume fraction, geometrical dimensions, deformation, strain, stress, strength, elastic moduli and thermal quantities for ceramic matrix composites.
- Nomenclature for constituents: The F/I/M convention (F = fiber reinforcement chemistry, I = interphase chemistry, M = matrix chemistry).
- Example: SiC/C/SiC for silicon carbide fiber, carbon interphase, silicon carbide matrix.
- Example for layered interphase: C/[C/SiC]f4/SiC.
- Symbol tables: Organized lists (Tables 1–4) of symbols related to physical quantities, geometrical quantities of test pieces, mechanical quantities and thermal quantities.
- Significance and use: Guidance on correct application of symbols, subscripts and modifiers (e.g., tensile/compressive subscripts, apparent vs effective dimensions when surface treatments are present).
- Normative references: Aligns with ISO 80000‑4 (Mechanics) and ISO 80000‑5 (Thermodynamics) for quantity and unit definitions.
Applications and users
ISO 19634:2017 is intended for:
- Materials scientists and engineers characterizing ceramic matrix composites (1D, 2D, xD materials).
- Test laboratories preparing reports of mechanical and thermal tests (tensile, compressive, flexural, shear, thermal expansion, etc.).
- Product developers, quality assurance and technical documentation teams who need consistent symbol usage in data sheets, specifications and publications.
- Standards writers and academics ensuring consistent notation across publications and cross-referencing other ISO methods.
Practical benefits include clearer test reports, consistent data exchange between suppliers and customers, and reduced risk of misinterpretation in engineering design and materials research.
Related standards
- ISO 80000-4 - Quantities and units - Part 4: Mechanics
- ISO 80000-5 - Quantities and units - Part 5: Thermodynamics
ISO 19634 was prepared by ISO/TC 206 (Fine ceramics) and is complementary to measurement method standards that define how the listed quantities are determined.
Keywords: ISO 19634:2017, ceramic matrix composites, notations and symbols, fine ceramics, advanced ceramics, mechanical properties, thermal characteristics, ISO 80000.