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Plastic deformation mechanisms in SiC-whisker-reinforced alumina

Journal Article · · Journal of the American Ceramic Society; (United States)

SiC-whisker-reinforced Al[sub 2]O[sub 3] samples (SiC[sub w]/Al[sub 2]O[sub 3]), obtained from three different manufacturers, containing 0-30 vol% SiC have been crept under compression at 1,400 C in flowing argon. Compressive creep tests and microstructural observations have been used to characterize the plastic deformation mechanisms. The presence of whiskers decreased the creep rate by reducing grain-boundary sliding. Damage formation was increased, however, because the whiskers acted as stress concentration sites. For specimens with whisker loadings greater than 15%, the absolute creep rate was not strongly dependent on whisker concentration, and the formation of cavitation damage was negligible below a critical stress that depended on the fabrication procedure of the specimen. This creep regime was characterized by a stress exponent of approximately 1, in which deformation occurred primarily by diffusional flow. For the materials with less SiC, the deformation occurred primarily by grain boundary sliding.

OSTI ID:
6210658
Journal Information:
Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 76:6; ISSN 0002-7820; ISSN JACTAW
Country of Publication:
United States
Language:
English