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Diffusional Crack Growth and Creep Rupture of Silicon Carbide Doped with Alumina
Author(s) -
Ohji Tatsuki,
Yamauchi Yukihiko
Publication year - 1994
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.1151-2916.1994.tb05348.x
Subject(s) - creep , materials science , silicon carbide , composite material , carbide , stress (linguistics) , grain boundary , diffusion creep , doping , activation energy , metallurgy , microstructure , chemistry , philosophy , linguistics , optoelectronics , organic chemistry
This study deals with tensile creep and crack growth behavior of silicon carbide doped with alumina at 1400°C. Excellent creep resistance was observed for stresses from 150 MPa to 200 MPa. From the creep exponent of 1.4 and the activation energy of 320 kj/mol, the principal creep mechanism was Coble creep. The creep failure was caused by slow crack growth from a preexisting flaw. The crack was found to grow subcritically along grain boundaries almost in isolation. The relation between the time–to–failure and the applied stress was well treated by a diffusive crack growth model, and the threshold stress of this material at 1400°C was estimated at 165 MPa.