Computational Design of Corrosion-resistant and Wear-resistant Titanium Alloys for Orthopedic Implants

TL;DR

This paper introduces a computational approach to designing titanium alloys with improved corrosion and wear resistance for orthopedic implants, balancing multiple material properties.

Contribution

It develops a multi-criteria computational method combining proxy descriptors and CALPHAD calculations to optimize alloy composition for biomedical applications.

Findings

Identified alloy compositions with enhanced corrosion resistance.

Demonstrated the role of silicon in improving alloy properties.

Provided phase diagrams and stability assessments for candidate alloys.

Abstract

Titanium alloys are promising candidates for orthopedic implants due to their mechanical resilience and biocompatibility. Current titanium alloys in orthopedic implants still suffer from low wear and corrosion resistance. Here, we present a computational method for optimizing the composition of titanium alloys for enhanced corrosion and wear resistance without compromising on other aspects such as phase stability, biocompatibility, and strength. We use the cohesive energy, oxide formation energy, surface work function, and the elastic shear modulus of pure elements as proxy descriptors to guide us towards alloys with enhanced wear and corrosion resistance. For the best-selected candidates, we then use the CALPHAD approach, as implemented in the Thermo-Calc software, to calculate the phase diagram, yield strength, hardness, Pourbaix diagram, and the Pilling-Bedworth (PB) ratio. These calculations are used to assess the thermodynamic stability, biocompatibility, corrosion resistance, and wear resistance of the selected alloys. Additionally, we provide insights about the role of silicon on improving the corrosion and wear resistance of alloys.