Abstract: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 TiAl_xSi_y 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.

Key words: TiC; silicon; Al-Si alloy; stability