Different phase transformation behaviors of B2-CuZr crystalline phase and their associated mechanical properties by molecular dynamics using different potentials

Abstract

Metastable CuZr-based alloys have attracted much attention due to their high glass-forming ability and shape memory effect. Many experiments have underscored the pivotal role of the B2-CuZr phase as an effective inclusion to improve both the strength and ductility of metallic glass matrix composites. The improved ductility can be attributed to the dilatation induced by martensitic transformation, while the strengthening effect is owed to the higher strength and hardness of the martensite phase compared to the austenite phase. Well-designed atomistic simulations can predict the mechanical behavior of materials before experiments and offer sufficient information on the atomic scale. The selection of an appropriate interatomic potential is a primary concern in any atomistic simulation and needs to be carefully considered to ensure reliable results. The uniaxial tensile behavior of B2-CuZr crystalline phase is investigated by molecular dynamics simulations using five typical potentials, namely the potentials developed by Mendelev-2007, Mendelev-2009, Mendelev-2016, Mendelev-2019 and Cheng-2009. The phase transformation behavior during tension, Young’s modulus, and yield strength of the simulated samples exhibit variations when different potentials are employed. Notably, only by employing Mendelev-2019 and Cheng-2009 potentials, the strength and Young’s modulus of the transformed phase are higher than the untransformed austenite phase, corresponding well with experimental results. This work emphasizes the impact of different interatomic potentials on phase transformation behaviors within a specific simulation context.