Issue
J. Phys. Colloques
Volume 51, Number C1, Janvier 1990
Proceeding of the International Congress
Intergranular and Interphase Boundaries in materials
Page(s) C1-1043 - C1-1048
DOI https://doi.org/10.1051/jphyscol:19901162
J. Phys. Colloques 51, C1-1043-C1-1048 (1990)
DOI: 10.1051/jphyscol:19901162

THE INTERFACIAL MICROSTRUCTURE OF SiC-WHISKER REINFORCED Si3N4

A.H. SWAN1, E. OLSSON2, R. LUNDBERG3 et G. L. DUNLOP4

1  Department of Physics, Chalmers University of Technology. S-412 96 Göteborg, Sweden
2  IBM Research Division, TJ Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598, USA
3  Swedish Ceramic Institute, Box 5403, S-402 29 Göteborg, Sweden
4  Department of Mining and Metallurgical Engineering, University of Queensland, St Lucia, Queensland 4067, Australia


Abstract
The fine scale interfacial microstructure of SiC whisker reinforced Si3N4 composites has been studied using analytical electron microscopy. The composites have been prepared in two different ways, by hot pressing and by nitrided pressureless sintering. Mechanical tests were performed at room temperature as well as at elevated temperatures. Debonded whiskers were found in heat treated materials and microcracks were found in samples strained at elevated temperatures. This suggests that a different mechanism was responsible for the fracture process at elevated temperatures. The fracture surfaces of samples tested at room temperature showed signs of whisker pull-out in a limited zone surrounding the fracture origin.