The last 30 years have seen a steady development in the range of ceramic materials with potential for high temperature engineering applications: in the 60s, self-bonded silicon carbide and reaction-bonded silicon nitride; in the 70s, improved aluminas, sintered silicon carbide and silicon nitrides (including sialons); in the 80s, various toughened Zr0 materials, ceramic matrix composites reinforced with silicon 2 carbide continuous fibres or whiskers. Design methodologies were evolved in the 70s, incorporating the principles of fracture mechanics and the statistical variation and time...