Electronic, mechanical, thermodynamic and vibrational properties of Cu-modified NiTi alloys: a first-principles study

Shape memory alloys (SMAs), known for their ability to return to their original shape after deformation, are highly sensitive to the alloying composition, which can significantly alter their transformation behavior and functional properties. In this study, we examined the influence of nickel substitution with copper on the structural, mechanical, thermodynamic, electronic, and vibrational properties of the B2 NiTi phase, at concentrations of up to 30 at% using density functional theory (DFT) with the ABINIT code. The validity of our calculations is confirmed by the calculated lattice parameters, which show good agreement with known theoretical and experimental data. The overall results highlight the impact of Cu incorporation on the stability of NiTi-based alloys, thus offering valuable insights for the design of advanced SMAs.