Mechanical and Biocompatibility Assessment of Direct Metal Laser Sintering Produced Ti6Al4V–Hydroxyapatite Composite for Orthopedic Implant Application

This work reports the characterization of Ti6Al4V-hydroxyapatite (Ti64-HA) composite fabricated using the direct metal laser sintering (DMLS) technique for orthopedic implant applications. Ti64-HA composite has gained wide attention due to its improved bioactivity. However, till now, no one has reported the mechanical, tribological, corrosion, and cell viability of DMLS-produced Ti64-HA composite. In the present study, three different compositions (0% HA, 5% HA, and 10% HA) were fabricated to evaluate the effect of HA concentration. Along with characterizations related to mechanical and biomedical properties, corrosion behavior was also evaluated in two different bio-media/environments, viz., physiological saline solution (PSS) and simulated body fluid (SBF), to check invitro degradation rate. The cell viability of all three samples was checked with the osteoblast cell line (MG63). The highest cell viability was obtained in the case of Ti64-10HA composite, and the lowest was obtained for Ti64 alloy. Apart from enhancement in biomedical properties, the addition of HA also lowered the Young’s modulus of elasticity and brought it close to typical human bone, which is a favorable attribute for avoiding stress shielding. Thus, in terms of mechanical properties, biocompatibility, and corrosion behavior, the Ti64-10HA composite was found to be better than Ti64-5HA composite and the Ti64 alloy.