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

Abstract

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.

Structure and properties of CoCrFeNiX multi-principal element alloys from ab initio calculations

“…Thus, we can conclude that the elastic properties are not much influenced by the unit cell size employed in the calculations or by the particular atomic configuration. A similar result was already observed in the TiZrNbTaMo alloy 63 and also in two-component alloys, 103 namely, that the elastic properties are not significantly affected by the atomic ordering but rather by the composition.…”

“…80 More details of the methodology used in this work are thoroughly described in our previous work. 63 The number of atoms in the unit cell for all the studied alloys is 2N, where N is the number of elements in the alloy. The exception is the base CoCrFeNi alloy that we use to test the importance of the unit cell size.…”

“…62 Recently, this method has proved to be useful in predicting the structure of MPEAs. 63 Another evolutionary design strategy has also been recently applied to the search of strong and stable MPEAs. 64 Here, we further test the ability of these kind of methods in predicting the crystal structure by comparing our new results for the CoCrFeNi-based MPEAs with the results from other methodologies, such as EMTO-CPA 47,[49][50][51][56][57][58] and SQS-DFT, 50 as well as with existing experimental data.…”

Research Progress of Titanium-Based High Entropy Alloy: Methods, Properties, and Applications

“…Moreover, the HEA design is not a simple mixing of elements, it is necessary to consider the interaction between elements that will affect the overall performance of the obtained alloy ( George et al, 2020 ). At present, the HEA design firstly is done through computer simulations in which the influence of thermodynamics and kinetics of the alloy needed to determine, also the impact of phase formation laws must be considered ( Koval et al, 2019 ). Computer simulation generally uses first-principle calculations and phase diagram calculations to predict the structure, phase stability, and mechanical properties of HEAs.…”

Study on Stability and Elastic Properties of β-TiX (X=Nb, Ta) Alloys From First-Principles Calculations

“…The study by Yu et al showed that the non-spherical distribution of electrons will lead to difficult plastic deformation of the alloy and high modulus. Koval et al, (2019) also analyzed the effect of electronic structure on the elastic properties of β-Ti alloys. Zhang et al, (2016) used the first-principles method to study the effect of alloying element content on the phase stability of binary titanium alloys.…”