The in-situ synthesized of TiC in Al melts based on Ti-Si-diamond system and its morphologies

In this work, diamond has been successfully introduced into Al melts to in-situ synthesis TiC based on Ti-Si-D system. It is found that both Ti and Al react with diamond during the addition of Ti-Si-D mixture into Al melts, and realize the reactive wetting of diamond. Ti and diamond reaction results in the TiC shell formation, while Al and diamond reaction forms Al4C3 and prevents the formed TiC shell from becoming dense. Once introduced into Al melts, the residual diamond prefers to react with Al to form Al4C3@TiC core-cell particles or Al(4)C(3)plates, and then Al4C3 reacts with Ti to synthesize TiC. The morphologies of the TiC particles synthesized by different processes are various. When TiC are formed by Ti and Al4C3 of Al4C3@TiC particles, Al@TiC core-shell particles are obtained and the TiC particles in the shell have different morphologies due to their mutual interference during growth. When TiC are formed by Ti and Al4C3 plates and can grow freely in Al melts, the octahedral TiC particles are obtained. 2020 The Authors. (C) Published by Elsevier B.V.