Premium
Fracture and Subcritical Crack‐Growth Behavior of Y‐Si‐Al‐O‐N Glasses and Si 3 N 4 Ceramics
Author(s) -
Bhatnagar Ajay,
Hoffman Michael J.,
Dauskardt Reinhold H.
Publication year - 2000
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.1151-2916.2000.tb01237.x
Subject(s) - materials science , silicon nitride , fracture toughness , ceramic , composite material , indentation , inert , silicon oxynitride , fracture mechanics , nitride , grain boundary , crack growth resistance curve , fracture (geology) , crack closure , microstructure , layer (electronics) , chemistry , organic chemistry
Fracture and environmentally assisted subcritical crack‐growth processes are examined in bulk Y‐Si‐Al‐O‐N oxynitride glasses with compositions typical of the grain boundary phase of silicon nitride ceramics. Both long‐crack (in compact tension specimens) as well as short‐crack behavior (using indentation techniques) were investigated to establish a reliable fracture toughness and to elucidate the anomalous densification behavior of the oxynitride glass. Environmentally assisted subcritical crack‐growth processes were studied in inert, moist, and wet environments under both cyclic and static loading conditions. Behavior is discussed in terms of the interaction of the environment with the crack tip. Likely mechanisms for environmentally assisted crack growth are discussed and related to the subcritical crack‐growth behavior of silicon nitride ceramics.