In-situ reaction mechanism of Ti₃AlC₂/TiAl₃ composite prepared by powder metallurgy

The layered MAX phase Ti₃AlC₂ is an excellent reinforcement for TiAl₃ matrix. However, unraveling the complex in-situ reaction mechanism of Ti₃AlC₂/TiAl₃ composites is a challenge of great scientific and practical significance. In this paper, Ti₃AlC₂/TiAl₃ composites were sintered at different temperatures from 630 to 1300 °C by using the TiH₂, Al and TiC powder as starting materials via powder metallurgy route. Then the samples were characterized using multiple advanced analytical tools to systematically investigate the in-situ reaction mechanism of the Ti₃AlC₂/TiAl₃ composites. The results indicate that the reinforcement Ti₃AlC₂ begins to generate at 1100 °C, and a coherent interface relationship is formed between the basal plane of hexagonal Ti₃AlC₂ phase and TiAl₃ matrix. Moreover, this coherent relationship can be inherited into the final Ti₃AlC₂/TiAl₃ composites, which is more conducive to the enhancement of interfacial bonding as well as better transfer of stresses, thus effectively improving the strength and toughness of the composite.