The introduction of SiC into Cu melts based on Ti–SiC system and its transformation

In this work, SiC particles with different sizes have been effectively introduced into Cu melts based on Ti–SiC system, and the types and microstructures of Ti–SiC reaction products are varied with the SiC size change. With small size, SiC can absolutely react with Ti to form TiC particles and Ti5Si3, while large SiC cannot react completely. In the latter case, besides TiC particles and Ti5Si3, the core–shell particles, including Cu@TiC, SiC@TiC, carbon derived from silicon carbide (SiC-CDC) @TiC and ternary layers SiC@SiC-CDC@TiC, can be formed. It is considered that the reaction of Ti–SiC in Cu melts not only has two alternative reaction path ways but also has two stages. The first stage is the instantaneous reaction between Ti and SiC during the addition and start with TiC formation, which realizes the reactive wetting of SiC by Cu melts and leads to the eventual formation of TiC or SiC@TiC core–shell particles. The second stage is the reaction between Ti and residual SiC in Cu melts which starts with the transformation of SiC into SiC-CDC and leads to the eventual formation of Cu@TiC, SiC-CDC@TiC or SiC@SiC-CDC@TiC core–shell particles.