Paper number 1351

THERMOMECHANICAL BEHAVIOUR OF 2D-SIC/SIC COMPOSITES WITH NANOSCALE-MULTILAYERED (PYC/SIC)N INTERPHASES

S. Bertrand, F. Germain, R. Pailler and J. Lamon

Laboratoire des Composites Thermostructuraux (UMR 5801 CNRS-SEP/SNECMA-UB1)
Université de Bordeaux 1, 3 Allée de la Boétie, 33600 Pessac, France

Summary

2D woven SiC/SiC composites, with nanoscale-multilayered (PyC/SiC)n interphases, have been made via chemical vapour infiltration of a preform of either Nicalon or Hi-Nicalon fibres. The nanoscale-multilayered (PyC/SiC)n interphases consist of n successive PyC-SiC sequences. In the present paper n = 10 and the thickness of the PyC and SiC sublayers was about 20 nm and 50 nm respectively. The influence of Hi-Nicalon fibres and multilayered interphases on the mechanical behaviour at room temperature and the lifetime in cyclic fatigue at 600°C and 1200°C was investigated. The Hi-Nicalon fibre and the multilayered interphases are shown to lead to improved 2D-SiC/SiC composites.

Keywords

interphase, mechanical properties, lifetime, cyclic fatigue, oxidation, ceramic matrix composite, multilayer.