Ab-initio simulation and experimental validation of beta-titanium alloys

TL;DR

This paper combines ab-initio quantum mechanical simulations with experimental validation to design and analyze beta-titanium alloys for biomedical use, focusing on non-toxic elements, phase stability, and elastic properties.

Contribution

It introduces a new integrated approach using density functional theory and experiments to optimize beta-Ti alloys for biomedical applications.

Findings

Validated theoretical predictions with experimental data.

Identified alloy compositions with desired phase stability and elastic properties.

Evaluated different modeling approximations for mechanical and thermodynamic properties.

Abstract

In this progress report we present a new approach to the ab-initio guided bottom up design of beta-Ti alloys for biomedical applications using a quantum mechanical simulation method in conjunction with experiments. Parameter-free density functional theory calculations are used to provide theoretical guidance in selecting and optimizing Ti-based alloys with respect to three constraints: (i) the use of non-toxic alloy elements; (ii) the stabilization of the body centered cubic beta phase at room temperature; (iii) the reduction of the elastic stiffness compared to existing Ti-based alloys. Following the theoretical predictions, the alloys of interest are cast and characterized with respect to their crystallographic structure, microstructure, texture, and elastic stiffness. Due to the complexity of the ab initio calculations, the simulations have been focused on a set of binary systems of Ti with two different high melting bcc metals, namely, Nb and Mo. Various levels of model approximations to describe mechanical and thermodynamic properties are tested and critically evaluated. The experiments are conducted both, on some of the binary alloys and on two more complex engineering alloy variants, namely, Ti-35wt.%Nb-7wt.%Zr-5wt.%Ta and a Ti-20wt.%Mo-7wt.%Zr-5wt.%Ta.