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Effect of Grain‐Boundary Phase on Dynamic Compression Fatigue in Hot‐Pressed Silicon Nitride
Author(s) -
Sharma Vinod,
NematNasser Sia,
Vecchio Kenneth S.
Publication year - 1998
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.1151-2916.1998.tb02304.x
Subject(s) - materials science , silicon nitride , grain boundary , composite material , nitride , amorphous solid , phase (matter) , yttria stabilized zirconia , silicon , metallurgy , ceramic , microstructure , crystallography , chemistry , cubic zirconia , organic chemistry , layer (electronics)
Two types of hot‐pressed silicon nitride, one having an amorphous grain‐boundary phase (6 wt% yttria, 3 wt% alumina) and the other having a predominantly crystalline grain‐boundary phase (8 wt% yttria, 1 wt% alumina), were tested on a split Hopkinson pressure bar with a momentum trap, such that, in each test, the sample was subjected to a single predefined stress pulse and then recovered without being subjected to any other loads. The specimens were loaded repeatedly with a triangular pulse of 3.2 GPa amplitude at a strain rate of approximately 400/s. The dynamic fatigue life of amorphous grain‐boundary‐phase silicon nitride was observed to be higher than that of the corresponding fatigue life of crystalline grain‐boundary‐phase silicon nitride. The difference in fatigue lives is correlated to the microstructural damage occurring in both materials.