PREPARATION AND MICROSTRUCTURE OF CARBON/CARBON COMPOSITES MODIFIED WITH Zr-Ti-C FABRICATED BY REACTED MELT INFILTRATION

摘要

A novel anti-ablation material of carbon/carbon (C/C) composites modified with the carbides of zirconium-titanium was prepared by reacted melt infiltration (RMI) and their synthetic mechanism and microstructure were investigated Carbon fiber felts were firstly densified by carbon using chemical vapor infiltration to obtain a porous C/C skeleton. The zirconium-titanium melt was then infiltrated into the porous C/C skeleton at high temperatures to obtain the final composites. Models based on these results were built up to describe the diffusion behavior of carbon atoms in the carbides and the kinetic process of RMI. The results also show that the synthesized composites have good interface cohesion between carbon fibers, pyrocarbon and carbide. The carbide with-high content of Zr atom in the final composites is composed of the main phase of Zr_(0.83)Ti_(0.17)C_(0.92), dispersively distributed with the phase of Ti_(0.82)Zr_(0.18)C_(0.92), while the carbide with high content of Ti composed of Zr_(0.57)Ti_(0.43)C_(1.01).