High temperature corrosion of carbon/carbon composites in Zr-Ti melts during liquid metal infiltration

The carbon/carbon composites with Zr-Ti-C were prepared by liquid metal infiltration (LMI) process. The chemical corrosion and thermal stress damage of carbon matrices in Zr-Ti melts were investigated. A corrosion mechanism and a method of rehabilitating defective materials were proposed. The results indicated that the internal carbon matrices of composites were not corroded by the Zr-Ti melts and their vapours. However, the superficial matrices contacting the melts were severely consumed. In addition, the release of thermal stress produced the defects. The flexural strength of the samples after LMI could be improved via a new deposition of pyrocarbon in the defects.