LAUSR

Abstract To improve the bioactivity of the Ti-Mo alloy, Ti-10Mo/xHA (hydroxyapatite, x = 3, 5, 7, 10, and 12 wt%) composites were fabricated by powder metallurgy for orthopedic applications. The effects of HA content on the microstructural evolution, mechanical properties, and biological activity of the composites were investigated. The results showed that the Ti-10Mo alloy exhibited a typical Widmanstatten structure (α + β), and the composites mainly consisted of α-Ti, β-Ti, and ceramic phases such as CaTiO3, Ti2O, Ca3(PO4)2, HA, CaO, and TixPy. With increase in the HA content, the β-Ti content decreased, while the contents of α-Ti and ceramic phases increased. The compressive strength decreased from 1526 to 615 MPa, the elastic modulus first increased and then decreased from 78 to 52 GPa. The excessive HA (12 wt%) led to a sharp decrease in the compressive strength and elastic modulus owing to increase in the number of pores and generation of microcracks. Many bone-like apatite layers were deposited on the surface of the Ti-10Mo/7HA composite after immersion in simulated body fluid for 7 d. Compared with the Ti-10Mo alloy, the Ti-10Mo/7HA composite showed better mechanical properties and biological activity and can be used as a potential orthopedic material.