Combustion synthesis of Ti3Si1−xAlxC2 solid solutions from TiC-, SiC-, and Al4C3-containing powder compacts

Preparation of the Ti3Si1−xAlxC2 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 Ti3Si1−xAlxC2 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.

► Ti3Si1−xAlxC2 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.
► Ti3Si1−xAlxC2 with a higher content of Al is more preferably formed from the TiC- and SiC-containing samples.
► The optimum yield of Ti3Si1−xAlxC2 is achieved by the TiC-added sample.
► The Al4C3-containing sample is not favorable for the formation of Ti3Si1−xAlxC2 through the SHS process.