Microstructure and mechanical properties of a novel Titanium-based alloy with high elastic strain for orthopedic implant applications

Abstract

This study develops a biocompatible Ti-37.5Nb-4.5Zr alloy for orthopedic implants, addressing strength-ductility and stress shielding issues by leveraging twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) effects, and controlled phase transformations among β, ω, α′, and α″ phases with comprehensive characterization, such as CALPHAD, dilatometry, X-ray diffraction (XRD), transmission electron microscopy (TEM), and mechanical testing. Results show a cold-rolled sample with a yield strength of 1050 ± 20 MPa, tensile strength of 1340 ± 15 MPa, elastic modulus of 40.5 ± 0.2 GPa, and 2.1 ± 0.2% elongation, while the annealed sample at 700°C for 30 min achieve 750 ± 10 MPa yield strength, 1050 ± 10 MPa tensile strength, 44.0 ± 0.4 GPa modulus, and 26.2 ± 1.1% elongation, demonstrating a balanced combination of strength, ductility, and elastic strain suitable for advanced orthopedic applications.