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Silicon Carbide Monofilament‐Reinforced Silicon Nitride or Silicon Carbide Matrix Composites
Author(s) -
Kodama Hironori,
Sakamoto Hiroshi,
Miyoshi Tadahiko
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.tb06174.x
Subject(s) - materials science , composite material , silicon carbide , fracture toughness , silicon nitride , ceramic matrix composite , flexural strength , fracture mechanics , toughness , ceramic , stress (linguistics) , protein filament , layer (electronics) , linguistics , philosophy
SiC‐monofilament‐reinforced SiC or Si 3 N 4 matrix composites were fabricated by hot‐pressing, and their mechanical properties and effects of filaments and filament coating layers were studied. Relationships between frictional stress of filament/matrix interface and fracture toughness of SiC monofilament/Si 3 N 4 matrix composites were also investigated. As a result, it was confirmed experimentally that in the case of composites fractured with filament pullout, the fracture toughness increased as the frictional stress increased. On the other hand, when frictional stress was too large (>about 80 MPa) for the filament to be pulled out, fracture toughnesses of the composites were almost the same and not so much improved over that of Si 3 N 4 monolithic ceramics. The filament coating layers were found to have a significant effect on the frictional stress of the SiC monofilament/Si 3 N 4 matrix interface and consequently the fracture toughness of the composites. Also the crack propagation behavior in the SiC monofilament/Si 3 N 4 matrix composites was observed during flexural loading and cyclic loading tests by an in situ observation apparatus consisting of an SEM and a bending machine. The filament effect which obstructed crack propagation was clearly observed. Fatigue crack growth was not detected after 300 cyclic load applications.