High-temperature compressive creep of liquid phase sintered silicon carbide

摘要: Creep of liquid phase sintered SiC has been studied at temperatures between 1,575 and 1,700 C in argon under nominal stresses from 90 to 500 MPa. rates ranged 3 {times} 10{sup {minus}8} {minus}6}/s, with an activation energy 840 {+-} 100 kJ/mol (corresponding carbon silicon self-diffusion), a stress exponent 1.6 0.2. The crept samples showed the presence dislocation activity, generally forming glide bands tangles. Degradation mechanical properties due cavitation or reaction additives was not detected. SEM TEM microstructural characterization analysis creep parameters leads conclusion that mechanisms operating are grain boundary sliding accommodated by lattice diffusion climb-controlled parallel. Other possible discussed data compared published data.