THE FRACTURE-BEHAVIOR OF SIC REINFORCED SIALYON CERAMIC-MATRIX COMPOSITES

This paper presents the results of a study carried out at the AEROSPAT IALE Joint Research Center on SiAlYON Matrix Composites reinforced wit h 0, 10, 20 and 30% of SiC whiskers. Firstly the test methodology for measuring the K1c is described. The SENB (Single Edge Notched Beam) sp ecimen pre-cracked in compression cycling is compared to the Chevron N otched bend bar test. In both cases the fracture toughness is measured in a bend test more adapted for tests at elevated temperatures. Then the crack propagation at elevated temperature of the composite for the four SiCw volume fractions is described and discussed in relationship with the theological behaviour of the matrix and the volume fraction of reinforcement.