Premium
Relationship between Microstructure, Toughening Mechanisms, and Fracture Toughness of Reinforced Silicon Nitride Ceramics
Author(s) -
Šajgalik Pavol,
Dusza J.,
Hoffmann M. J.
Publication year - 1995
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.1151-2916.1995.tb08031.x
Subject(s) - microstructure , materials science , fracture toughness , sintering , ceramic , toughening , silicon nitride , composite material , volume fraction , toughness , layer (electronics)
Different microstructures in Si 3 N 4 ceramics containing Y 2 O 3 and Al 2 O 3 as sintering additives were prepared by two‐step sintering. Pull‐out and elastic bridging were most frequently observed as the toughening mechanisms in samples with fine‐grained microstructures having needlelike β‐Si 3 N 4 grains with diameters of <1 μm. Crack deflection was the main toughening mechanism observed in samples with coarse‐grained microstructures having grains with diameters of >1 μm. The values of fracture toughness were varied from 6.1 to 8.2 MPa·m 1/2 with respect to the microstructural characteristics, characterized by the volume fraction of needlelike grains and their diameter.