Research on suitable strength, elastic modulus and abrasion resistance of Ti–Zr–Nb medium entropy alloys (MEAs) for implant adaptation

Attributed to their excellent strength, toughness, hardness, wear resistance and corrosion resistance, some Ti-rich high entropy alloys (HEAs) and medium entropy alloys (MEAs) are develop as one of potential implant materials, however poor ductility at room temperature and high elastic modulus limit their application. To obtain implant materials more suitable for human bone, five Ti–Zr–Nb MEAs (TiZrNb, Ti40Zr40Nb20, Ti45Zr35Nb20, Ti45Zr45Nb10, and Ti50Zr40Nb10) were designed and fabricated. All alloys possessed BCC structure, low elastic modulus (52 ± 2–73 ± 3 GPa), and high yield strength (675 ± 18–830 ± 21 MPa) with elongation over 11%. The solid solution strengthening model and transition metal bond energy model were used to analyze their yield strength and elastic modulus, and the latter can make up for the limitations of concentration (VEC) in predicting elastic modulus. The abrasion test shows that their corrosion resistance is equivalent to that of Ti6Al4V and wear loss of MEAs ranges from 0.02054 mm3 to 0.1164 mm3.