Effect of interfacial microstructure on TiAl-Ti₃Al biphase alloy was studied via molecular dynamics

The TiAl-Ti₃Al biphase alloy is widely used in high-tech fields. The evolution of its interfacial microstructure affects alloy performance. But the impact of the biphase interfacial microstructure on mechanical properties under external forces is unknown. For the purpose of attaining a more profound comprehension of TiAl alloys and facilitating their extensive employment. In this work, the evolution of the γ(TiAl)/α₂(Ti₃Al) interface microstructure under external force was investigated by the nanoindentation model of MD simulation. The results showed that the γ(TiAl)/α₂(Ti₃Al) interface microstructure can hinder the motion of interface atoms under the spherical nanoindenter’s action. The atoms moved parallel to the interface, enhancing the alloy’s deformation resistance. During indentation, dislocations slipped from the Ti₃Al phase to the TiAl phase, but not vice versa. Moreover, the phase difference led to significantly different elastic recovery rates, shear strains, and plastic deformation capabilities.