Evolution characteristics of topologically close-packed structures during rapid solidification of TiAl alloy

Abstract

<p indent="0mm">Rapid solidification is one of the material processing methods. In this study, the rapid solidification process of TiAl alloys at a cooling rate of 2 ×<sc> 10¹¹ K/s</sc> was simulated using molecular dynamics. The properties of the system were analyzed using the potential energy, pair distribution function, largest standard cluster analysis (LaSCA), and visualization methods. Notably, after the melt processes of supercooled liquid and solid, the system with a high Al content undergoes amorphization, and that with a low Al content undergoes crystallization. In the amorphous system, topologically close-packed (TCP) LaSCA can well characterize the microstructure of TiAl alloy. Notably, different subsets of TCP structures show different evolutionary trends during amorphization. Different evolutionary characteristics provide proof that explains the vitrification characteristics of TiAl alloy. This finding can be the basis for the analysis of the correlation between glass-forming capability and amorphous structures.