Influence of Si on stability of TiC in Al melts

The influence of Si on the stability of TiC in Al melts was studied. It is found that TiC particles in Al melts become unstable with the addition of Si. When the melting temperature is below 890 °C, TiC will react with Al and Si to form TiAlxSiy and Al4C3 phases. But if the melt temperature is above 890 °C, TiC will react with Al and Si to form to Ti3SiC2 and Al4C3. It is considered that the influence of Si on the stability of TiC in Al melts is due to its incursion into TiC crystal lattice during the holding, which will cause serious lattice distortion in TiC and then speed up the out-diffusion of surrounded C atoms.