Fracture and creep of an Al2O3-SiC(whisker-)TiC(particle) composite.

摘要

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.