Mechanical properties, corrosion behavior and cytotoxicity of Ti-6Al-4V alloy fabricated by laser metal deposition

Abstract

Ti-6Al-4V (TC4) is a widely used biomaterial due to the combination of excellent mechanical properties, corrosion resistance and biological properties. Laser metal deposition (LMD), an efficient and rapid additive manufacturing technology, is very suitable for biomaterial Ti alloy based implants for a customized design. The microstructure evolution and mechanical properties of TC4 samples fabricated by LMD with different scanning approaches were systematically studied in comparison with its wrought counterpart. Large-area mapping (LAM) electron backscatter diffraction (EBSD) results show that the one-way scanning produces finer grains and stronger texture index in the 〈 0001 〉 direction than those of the cross scanning equivalents. Moreover, the former has higher ultimate tensile strength and plasticity. Electrochemical experiments and in vitro biosafety evaluations were carried out to verify the feasibility of TC4 for long-term services in the body with respect to MC3T3-E1 cells. This work could promote the employment of LMD to build high-quality metal implants for medical applications. • Large temperature gradients lead to the formation of martensite in the LMD process. • One-way scanning has higher strength and ductility than cross scanning. • Corrosion resistance of one-way scanning is better than that of cross scanning. • The good biocompatibility of LMD TC4 samples is confirmed in vitro.