Phase composition, microstructure and in vitro bioactivity of laser cladding CaO-ZrO2-SiO2 system coatings on titanium alloy

The bioactive coatings were prepared by laser cladding CaO-ZrO2-SiO2 system coatings on titanium alloy (Ti6Al4V). The cross-section morphologies of the coating are cellular crystal and cellular-dendrite structure. With the increase of ZrO2 content, the structure becomes coarse. The coating is mainly composed of CaTiO3, CaO, α-Ca2(SiO4), SiO2 and TiO2. When 5 mol% ZrO2 was added, CaZrO3 appears. With the increase of ZrO2 content, ZrO2 appears and CaO disappears. The surface of these coatings are coarse, accidented and partial porous. After soaking in simulated body fluid (SBF), apatite is formed on the coating surface.