Fracture and creep of an Al{sub 2}O{sub 3}-SiC(whisker)-TiC(particle) composite.

High-temperature fracture strength and compressive creep of an electrodischarge-machinable composite, Al{sub 2}O{sub 3}-30.9 vol.% SiC whiskers-23 vol.% TiC particles have been studied to 1200 C and 1450 C, respectively, in inert atmosphere. Microstructures of fractured and deformed specimens were examined by scanning and transmission electron microscopy. Fast fracture occurred at T {le} 1200 C. Steady-state creep was achieved for T > 1350 C at stresses < 80 MPa, with the rate-controlling mechanism being partially unaccommodated grain-boundary sliding, with a stress exponent of {approx}1 and an activation energy of {approx}470 kJ/mol