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Si 3 N 4 /SiC‐Whisker Composites without Sintering Aids: II, Fracture Behavior
Author(s) -
Pezzotti Giuseppe,
Tanaka Isao,
Okamoto Taira
Publication year - 1990
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.1151-2916.1990.tb06713.x
Subject(s) - whisker , materials science , composite material , fracture toughness , sintering , whiskers , composite number , toughening , fracture (geology) , fracture mechanics , toughness
The fracture behavior of an Si 3 N 4 /SiC‐whisker composite fabricated without sintering aids is investigated using a double approach based on the examination of R ‐curve behavior and a statistical analysis of crack propagation. In the composite with 20 vol% whisker, a 30% increase in toughness over the matrix value can be attributed to crack‐tip phenomena. Strong interfacial bonding prevents any contribution to toughening by mechanisms operating in the wake region of the crack. Based on experimental observations of microfracture in both SiC whiskers and Si 3 N 4 grains, toughening caused by crack‐tip phenomena is quantitatively discussed in terms of fracture energy and whisker‐distribution parameters.