A molecular dynamics simulation-based laser melting behavior analysis for Ti–Al binary alloy

Abstract

Due to the lack of theoretical basis for the determination of process parameters, there are problems such as incomplete melting and excessive melting in the molten pool for laser processing, which ultimately cause the increase of defects such as air hole and crack. The melting behavior of Ti–Al binary alloy during laser processing is studied on the atomic scale by molecular dynamics simulation. The embedded atom method potential is adopted to establish the melting model of Ti–Al binary alloy. According to the changes of temperature, atomic structure and mean square displacement, the influence of different process parameters on the melting behavior of Ti–Al binary alloy is discussed. The results show that a short temperature drops from initial melting to complete melting. Mean square displacement increases rapidly with the increase of laser time after completely melting. The atoms start to move violently and the atomic structure is completely transformed into other structure. The heating and cooling rate increases with the increase of power. The laser power has little effect on the overall distribution of atoms after completely melting and only affects the variation rate of various physical quantities in melting process. The research results provide a deeper practical and theoretical evidence for the determination and optimization of the 3D printing and laser heat treatment.