Molecular dynamics simulations of rapid solidification of NiTi alloy under various pressure amounts

NiTi alloy is one of the materials that can recover its original shape after deformation. This material is categorized as a shape memory alloy. NiTi alloy exhibits high elasticity and excellent corrosion resistance. It is typically used in medical applications, such as braces, heart stents, and bone implants, because of its biocompatibility. The properties of NiTi alloy are very sensitive to the ratio of Ni and Ti atoms and are affected by the treatment during production. Based on the molecular dynamics simulation results, we report the effect of the pressures applied during the rapid solidification on the local crystal structures formed in the glassy NiTi alloy. From the bond-angle analysis, we found that the percentages of the fcc and bcc local structures increase at higher pressures. Meanwhile, the percentage of icosahedral local structure is maximum at a pressure of 50 GPa, which is low in the hcp local structure.