Premium
Effect of Silica and Processing Environment on the Toughness of Alumina Composites
Author(s) -
Smith S. M.,
Scattergood R. O.,
Singh J. P.,
Karasek K.
Publication year - 1989
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.1151-2916.1989.tb09719.x
Subject(s) - whiskers , materials science , fracture toughness , composite material , composite number , hot pressing , whisker , degradation (telecommunications) , toughness , transgranular fracture , oxygen , microstructure , grain boundary , chemistry , intergranular fracture , telecommunications , organic chemistry , computer science
Results are presented for the effect of the hot‐pressing environment and the oxygen content of Sic whiskers on the fracture toughness of an A1 2 0 3 ‐matrix composite reinforced with 15 vol% Sic. For the composite with Sic whiskers having a 55 at.% oxygen layer, the fracture toughness (K ic ) decreases from 8.03 to 6.64 MPa‐m 1/2 when the hot‐pressing environment is changed from argon to a vacuum of ∼6.7 × 10 −2 Pa. The results indicate that the decrease in K lc of the composite is related to the degradation of Sic whiskers by reaction with SiO 2 , which is enhanced in a vacuum environment where the reaction products are constantly removed.