Laser cladding of HA/Ti composite coating on NiTi alloy

To accelerate the bone growth around a metallic implant and to achieve the mechanical characteristics needed for biomedical applications, a hydroxyapatite/pure titanium (HA/Ti) composite coating was produced on NiTi alloy substrate by laser cladding. The experimental results showed that an excellent metallurgical bonding between the coating and the substrate was obtained. Owing to decomposition of HA under irradiation of high power laser, the microstructures of coating were mainly composed of CaO, CaTiO3, titanium phosphide and HA phases. In vitro experimental result demonstrated that HA/Ti composite coating made the bioactivity of NiTi alloy improved remarkably while restraining Ni ion from releasing.