Study on microstructure, microhardness, bioactivity, and biocompatibility of La₂ O₃ -containing bioceramic coating...

To solve the lack of strength of calcium phosphate ceramic coatings in load-bearing applications, gradient Ca-P bioceramic coatings doped with La₂ O₃ and SiO₂ are fabricated by laser cladding on Ti-6Al-4 V. The effect of SiO₂ on microstructure, microhardness, bioactivity, and biocompatibility of coatings was investigated. The experimental results illustrate that the coating doped with La₂ O₃ and SiO₂ has excellent metallurgical bonding. The XRD analysis confirms that the amount of hydroxyapatite and tricalcium phosphate in the coating reached maximum when doping amount of SiO₂ is 10 wt %. SiO₂ -doped coatings show a significantly higher bone-like apatite precipitation after immersion in SBF than that of other coatings. in vitro experiment also shows that coating with 10 wt % SiO₂ is more suitable for the attachment and proliferation of MG63 cells, indicating that coating with 10 wt % SiO₂ exhibits best bioactivity and biocompatibility. These results suggest that the addition of SiO₂ improves the bonding strength, bioactivity, and biocompatibility of coatings.