Hydroxyapatite reinforced with Ti-Fe particle: correlation between composition, microstructure and mechanical properties

Composites of hydroxyapatite (HA) with 5 wt-% Ti-Fe reinforcing particles were pressureless sintered in vacuum at a temperature range between 950 and 1100 degrees C. It was found that although the decomposition of HA and interaction between HA and Ti occurred, the desirable Ti phase still remained in the composites sintered at all temperatures. The outer Ti shell thickness of the distinctive core-shell Ti-Fe particles was observed to become larger as the sintering temperature increased. It was also found that minor pores appearing near the interface were beneficial to obtain appropriate interfacial bonding between HA matrix and Ti-Fe particles. The composite sintered at 1050 degrees C exhibited superior flexural strength, fracture toughness, and fatigue resistance owing to the remained Ti phase and dense microstructure as well as good interfacial bonding.