Very low elastic modulus Ti alloys obtained by Laser Directed Energy Deposition to avoid bone resorption in bone implants

Abstract

The elastic modulus of the cortical bone is below 30 GPa, whereas biomedical titanium implants exhibit an elastic modulus above 100 GPa. This mismatch in the elastic modulus can lead to bone resorption caused by the stress-shielding effect and poor osseointegration of the implant. This study aimed to determine whether the intense <100> fiber texture developed in Laser Directed Energy Deposition of beta-type Ti alloy ingots, results in a significant reduction in the elastic modulus. We demonstrated that laser-deposited beta-type Ti-42Nb (wt%) alloy ingots exhibit anisotropic mechanical properties. A low elastic modulus (below 50 GPa) and a high yield strength (above 700 MPa) were obtained in the building direction because of the intense <100> fiber texture. The novel laser deposited Ti-42Nb alloy also shows excellent biological performance in vitro, which suggests its suitability for biomedical applications.