Design and Fabrication of a 5Ti5Zr5Nb1Sn High‐Entropy Alloy as Metallic Biomedical Material

Herein the present work, the thermodynamic, physical, and mechanical properties of different random solid solution structure models are first calculated based on first‐principles calculation method, and the optimal composition ratio of 5Ti5Zr5Nb1Sn is quickly selected as a new biomedical high‐entropy alloy (HEA) with a low elastic modulus and high strength–ductility balance. Then, 5Ti5Zr5Nb1Sn HEA is prepared by vacuum‐melting method. The microstructure characterization results show that the actual composition of 5Ti5Zr5Nb1Sn HEA corresponds to the calculated target composition, and the HEA consists of two phases BCC1 and BCC2 with distinct color and structure. The compressive yield strength and compressive elongation of the 5Ti5Zr5Nb1Sn HEA are 1171.2 MPa and 29.03%, respectively. The compressive elastic modulus is 22.4 GPa, which is within the range of human bone elastic modulus (10–30 GPa). There are many tiny dimples and small tearing edges in the compression fracture, showing obvious plastic deformation characteristics. The analysis results of potentiodynamic polarization curve show that the corrosion resistance of 5Ti5Zr5Nb1Sn HEA is equivalent to that of pure titanium. Therefore, 5Ti5Zr5Nb1Sn HEA possesses the characteristics of high strength and ductility, low elastic modulus, and excellent corrosion resistance, and has the potential to be used as metallic biomedical materials.