Study on the Preparation Process of TiAl Alloy by Self-Propagating Metallurgy

As one of the most important routes for the preparation of high-temperature materials, self-propagating metallurgy has clear advantages in preparing high melting point alloys containing titanium, tungsten and other components. In this study, the effects of basic reaction thermodynamics, composition and proportion of reducing agent, slagging agent addition, and other factors regarding the rate and stability of self-propagating reactions in the process of preparing TiAl alloy by self-propagating metallurgy were examined. Also, the stable self-propagating heat transfer process was calculated. The results showed that stable reaction conditions for preparing TiAl alloy by self-propagating metallurgy were 3200 J/g of heat effect per unit mass using an Al-Ca compound reducing agent, in which Ca accounts for 15 wt.% of the reducing agent. After the reaction was completed, a wrapped structure of alloy surrounded with slag was obtained. The slag composition was mainly (CaO)(12) (Al2O3)(7) and the alloy contents of Ti, Al, and O at 52.00, 47.90 and 0.269 wt.%, respectively. Moreover, stability was mainly related to the physicochemical properties of the feedstock, reactor specifications and feeding rate. The approximate feeding rate range can be calculated for different specifications of reactors and raw material composition, which provided data support for potential industrialization.