Ceramics: Structure, Processing and Brittle Strength
The essential framework for understanding ceramic bonding, porosity, flaw sensitivity, thermal resistance and processing routes.
What defines a ceramic
Ceramics are inorganic, non-metallic solids whose behaviour is governed by strong ionic, covalent or mixed bonding. These bonds usually produce high stiffness, hardness, melting resistance and chemical stability, but they also restrict dislocation motion and limit room-temperature plasticity.
Why defects dominate strength
The practical strength of a ceramic is controlled less by ideal bond strength than by the largest critical flaw. Pores, machining damage, inclusions and surface cracks concentrate stress. Strength therefore varies statistically and depends strongly on specimen size, surface finish and processing quality.
Processing routes
Powder preparation, shaping, binder removal and sintering form the core route for most technical ceramics. Slip casting, pressing, extrusion, injection moulding and additive methods differ mainly in how they pack particles and control geometry before densification.
Thermal and environmental behaviour
Low thermal expansion, refractory stability and oxidation resistance make ceramics valuable at high temperature. Thermal shock resistance, however, depends on the combined effects of expansion coefficient, conductivity, modulus, strength and component geometry.
Working rule
Treat density, flaw population and surface condition as first-order design variables. A ceramic grade name alone never defines component reliability.