Compatibility of a V-15Cr-5Ti alloy with SiC at high temperatures

To clarify the chemical compatability between a V-15Cr-5Ti alloy and silicon carbide, the extent of reaction, the reaction products and the structure of reaction layer were studied at temperature ranging from 1423 to 1523 K in an argon gas stream. The reaction layers formed in the interfacial reactions consisted of the silicides, V5Si3 and V3Si, and minor amounts of TiC over the temperature range, and a ramarkable internal titanium carbide was also observed. The enrichment of chromium in the alloy matrix adjacent to the reaction layer was caused by the preferential diffusion of vanadium toward the SiC side. The growth of reaction layers followed a parabolic rate law. The parabolic growth rate constant was expressed by kp (m2s-1) = 1.8x10-8exp(- 197 kJ mol-1/RT). (orig.)