Adhesion strength of plasma-sprayed hydroxyapatite coatings on laser gas-nitrided pure titanium

A layer of bioceramic HA was coated on laser gas-nitrided pure titanium and grit-blasted pure titanium substrates using plasma-spraying technique, respectively. X-ray diffraction analysis showed that the microstructures of the coating were mainly composed of HA, amorphous calcium phosphate (ACP) and some minute phases of tricalcium phosphate (TCP, α-TCP and β-TCP), tetracalcium phosphate (TTCP) and calcium oxide (CaO). The experimental results showed that the 3-D TiN dendritic scaffold structure produced on the surface of pure titanium using laser gas nitriding technique in advance could anchor the HA coating and improved the interfacial adherence significantly as compared with that on the grit-blasted surfaces.