Self-propagiating high-temperature synthesis in $\mathrm{Ti}$–$\mathrm{Al}$–$\mathrm{Mn}$

Alloys based on the $\mathrm{Ti}$–$\mathrm{Al}$–$\mathrm{Mn}$ ternary system are among the most important in the development of doped titanium alloys for various purposes. In this work, an alloy made of $42.9\%$ of $\mathrm{Ti}$, $24.3\%$ of $\mathrm{Al}$, and $32.8\%$ of $\mathrm{Mn}$ (by wt.) is obtained via self-propagating high-temperature synthesis (SHS) during a thermal explosion. X-ray diffraction analysis shows that the final synthesis product containsa cubic $\mathrm{TiMn}_{0.32}\mathrm{Al}_{2.68}$ phase, a hexagonal $\mathrm{TiMn}_{0.755}\mathrm{Al}_{1.246}$ phase, and a binary $\mathrm{Mn}_3\mathrm{Al}_2$ phase. The porosity of synthesized samples is rather high $\approx41\%$), and they contain many pores (up to $300-400\mu$m). Phase formation may be due to the fact that the maximum temperature reached during the combustion of this system in the SHS process is insufficient for complete interaction with the formation of a $\mathrm{Mn}_2\mathrm{Ti}$ intermetallic phase and the dissolution of aluminum $\mathrm{Al}$ in it with the formation of a solid solution $(\mathrm{Mn}, \mathrm{Al})_2\mathrm{Ti}$. This promotes the formation of intermediate intermetallic phases, which can be in equilibrium with the liquid phase up to a melting point of titanium.