Abstract

Preparation of the Ti₃Si_1−xAl_xC₂ solid solution with x = 0.2–0.8 was investigated by self-propagating high-temperature synthesis (SHS) using TiC-, SiC-, and Al₄C₃-containing powder compacts. Due to the variation of reaction exothermicity with sample stoichiometry, the combustion temperature and reaction front velocity decreased with increasing Al content of Ti₃Si_1−xAl_xC₂ for the TiC- and Al₄C₃-added samples, but increased for the samples with SiC. In contrast to the formation of Ti₃(Si,Al)C₂ as the dominant phase for the TiC- and SiC-added samples, TiC was identified as the major constituent in the final products of samples adopting Al₄C₃. In addition, the evolution of Ti₃(Si,Al)C₂ was improved by increasing the Al content of the TiC- and SiC-added powder compacts, but deteriorated considerably upon the increase of Al₄C₃ in the Al₄C₃-containing sample.

Highlights

► Ti₃Si_1−xAl_xC₂ solid solutions with x = 0.2–0.8 are synthesized as the dominant phase from self-sustaining combustion of TiC- and SiC-added powder compacts. ► Ti₃Si_1−xAl_xC₂ with a higher content of Al is more preferably formed from the TiC- and SiC-containing samples. ► The optimum yield of Ti₃Si_1−xAl_xC₂ is achieved by the TiC-added sample. ► The Al₄C₃-containing sample is not favorable for the formation of Ti₃Si_1−xAl_xC₂ through the SHS process.