Elastic properties of the TiZrNbTaMo multi-principal element alloy studied from first principles

The TiZrNbTaMo multi-principal element alloy has been postulated as a new potential material for biomedical applications, such as orthopedic implants. Besides the good biocompatibility of the constituent atoms, the TiZrNbTaMo alloy also exhibits excellent corrosion resistance and mechanical properties, according to recent experimental studies. Motivated by these experiments, here we investigate with density functional theory (DFT) the structure, as well as the elastic and electronic properties, of the equiatomic and nearly-equiatomic TiZrNbTaMo alloys. By combining evolutionary algorithms with DFT calculations of the energy, we can correctly predict the crystal structures of the two phases that are identified in experiments. The corresponding elastic properties, which are also calculated with DFT, are in good qualitative agreement with the experimental observations. The analysis of the electronic properties allows us to explain the differences in the elastic moduli between the two phases in terms of the differences in both the electron density distribution and the bonding-states occupation.