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Plastic Deformation Mechanisms in SiC‐Whisker‐Reinforced Alumina
Author(s) -
ArellanoLópez Antonio R.,
DomínguezRodríguez Arturo,
Goretta Kenneth C.,
Routbort Jules L.
Publication year - 1993
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1993.tb03921.x
Subject(s) - whisker , materials science , creep , whiskers , composite material , grain boundary sliding , deformation (meteorology) , cavitation , stress (linguistics) , grain boundary , deformation mechanism , diffusion creep , microstructure , thermodynamics , linguistics , physics , philosophy
SiC‐whisker‐reinforced Al 2 O 3 samples (SiC w /Al 2 O 3 ), obtained from three different manufacturers, containing 0–30 vol% SiC have been crept under compression at 1400°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.