Fabrication of bioactive HA/Ti composite coating by laser cladding

To accelerate the bone growth around a metallic implant and to achieve the mechanical characteristics needed for biomedical applications, a HA/Ti composite coating was produced on NiTi alloy substrate by laser cladding. The chemical compositions, microstructures and surface morphology of the cladded layer were analyzed using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffractometry (XRD). 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 in bioceramics coating were mainly composed of CaO, CaTiO3, Ti4P3, and HA phases. In vitro experimental result showed that HA/Ti composite coating made the bioactivity of NiTi alloy improve remarkably, which would promote the bone growth and could restrain Ni ion releasing from NiTi alloy.