Mechanisms of Metal-Slag Separation Behavior in Thermite Reduction for Preparation of TiAl Alloy

Thermite reduction as one of the most promising methods for preparation of TiAl alloy, the metal-slag separation behavior in the whole process of chemical reaction, including both the alloy components and slags to be removed, is still ambiguous. In this paper, the two-step nucleation mechanism was applied to investigate the metal-slag separation behavior in the thermite reduction process for the preparation of TiAl alloy, which was confirmed by thermodynamic calculation based on density functional theory. Moreover, the component of products acquired from thermite reaction was characterized and analyzed by x-ray diffractometer, scanning electron microscope and transmission electron microscope, respectively. According to the results of the experiment and calculation, the formation and separation mechanism between alloy and slag in the process of preparing TiAl alloy via thermite reduction is visualized, which is universal in the whole metallurgical procedure involving redox and slag-making process.