# Enhancing Solid Solution Strengthening of TiZrNb Alloys via W and Cr Alloying: First-Principles Insights into Mechanical Properties

## TL;DR

This study explores how adding tungsten and chromium affects the strength and properties of TiZrNb alloys using computational methods.

## Contribution

A modified Senkov approach was proposed to improve yield strength estimation in TiZrNb alloys through W and Cr alloying.

## Key findings

- W and Cr reduce the lattice constant of TiZrNb alloys.
- W improves elastic modulus and solid solution strengthening, while Cr enhances bulk modulus at high levels.
- The modified Senkov approach improves yield strength estimation accuracy.

## Abstract

This work investigated the effects of varying tungsten (W) and chromium (Cr) contents on the lattice constant, elastic properties, yield strength, and electronic structure of TiZrNb alloys via first principles and the Special Quasi-Random Structure (SQS). A modified Senkov approach, considering the local atomic environment to estimate yield strength was suggested. Analysis indicated that W and Cr decrease the lattice constant of the TiZrNb alloy. W could improve the elastic modulus of material and solid solution strengthening effect, but Cr only enhanced the bulk modulus at high levels. The alloying of W and Cr was not beneficial for enhancing the plasticity. Cr was more significant in damaging mechanical isotropy. The modified Senkov approach improved the estimation accuracy of yield strength. Electronic property analysis indicated that W and Cr could lower the Fermi level to enhance the stability of the phase. Their covalent interactions helped to enhance strength. At present, the accuracy of the theoretical predictions has improved, relative to the experimental values. This work will provide guidance for the design and optimization of TiZrNb-based alloys.