Joining of C/C-SiC using boron-modified phenolic resin with SiO2 and B4C additives

Joining of carbon fibre reinforced C-SiC dual matrix composite has been realized through a reaction joining process using boron-modified phenolic resin with B4C and SiO2 additives. The effect of the technological parameters on the strength of joints was investigated. The optimized technological parameters are the curing temperature of 200 degrees C, the curing time of 2 hours and the curing pressure of 30 kPa, under which conditions, the obtained strength of the joint is equal to 82.6% of that of the substrate. The interlayer composed of Si, C, B and O is basically uniform and dense. There are no obvious cracks nor pores at the interfaces. The elements migrate across the interfaces, contributing to the enhancement of the joint strength. The results of heat treatment at 1500 degrees C show good heat resistance of the joints. The B4C and SiO2 additives contribute to the densification of the interlayer and the adhesion at the interfaces.