Volume 8, Issue 3, 1999

Effect of PIP Cycles on Fracture Behaviour in Unidirectional SiC FibRE-Reinforced SiC Matrix Composite

H. Kakisawa, Y. Kagawa^*,

Institute of Industrial Science, The University of Tokyo, 7-22-1, Roppongi, Minato-ku, Tokyo 106, Japan, Tel: 81-3-3402-6231 ex. 2436, Fax: 81-3-3402-6350, e-mail: kagawa@iis.u-tokyo.ac.jp

M. Takeda, Y. Imai, H. Ichikawa

Research Laboratory, Nippon Carbon Co. Ltd., Shin-urashima-Cho, Yokohama, 221 Japan

^*Corresponding author

ABSTRACT

The effect of pore volume fraction in unidirectional SiC fibre (Nicalon^TM)-reinforced SiC matrix composite fabricated by polymer infiltration pyrolysis (PIP) process on three-point bend fracture behaviour has been studied. The pore volume fraction, f_u, is varied by changing the number of PIP cycles, N. Results shows that the shear fracture mode is dominant at f_u greater or equal than 0.36 and the strength increased with the decrease of f_u. On the other hand, the tensile mode was dominant at f_u less or equal than 0.17 and the tensile strength was independent of f_u. Transition of the fracture mode occurred when the ratio of shear strength to constant tensile strength was reached approximately 1/30.