Characterization of TiN−HA nanocomposite developed through rapid microwave sintering route at high temperature

Titanium is one of the most suitable metals used in medical implants. Titanium alloys and titanium-based ceramics are widely used in orthodontics and orthopedic applications. In addition, titanium-based composites are preferred biomaterials for orthopedic applications and bioactive coatings. This work focuses on using relatively stable TiN material for the fabrication of TiN−HA composite through a rapid sintering technique at a process temperature of ∼1400–1450°C in a modified domestic microwave applicator at 800 W power. Microwave sintered nanocomposites were characterized in terms of density, measurement of microhardness, analysis of microstructures, and indentation fracture toughness. Sintered nanocomposites (with 15 wt% and 25 wt% HA) achieved ∼95% densification with comparable microhardness with respect to bulk TiN. However, the fracture toughness of the nanocomposites was compromised with the addition of the brittle HA phase when compared with pure TiN. The XRD results revealed an interaction between the constituent phases resulting in the formation of calcium titanate (CaTiO₃) and α-tri calcium phosphate (α-Ca₃(PO₄)₂) due to high processing temperature. Furthermore, microstructures clearly show good bonding between particles. The developed nanocomposites exhibited reasonable properties with biocompatible phases; consequently, the nanocomposites can be candidates for coating other metals and inert biomaterials.