Study on microstructure, microhardness, bioactivity, and biocompatibility of La₂O₃‐containing bioceramic coating doping SiO₂ fabricated by laser cladding

Abstract

To solve the lack of strength of calcium phosphate ceramic coatings in load-bearing applications, gradient Ca-P bioceramic coatings doped with La 2 O 3 and SiO 2 are fabricated by laser cladding on Ti-6Al-4 V. The effect of SiO 2 on microstructure, microhardness, bioactivity, and biocompatibility of coatings was investigated. The experimental results illustrate that the coating doped with La 2 O 3 and SiO 2 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 SiO 2 is 10 wt %. SiO 2 -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 % SiO 2 is more suitable for the attachment and proliferation of MG63 cells, indicating that coating with 10 wt % SiO 2 exhibits best bioactivity and biocompatibility. These results suggest that the addition of SiO 2 improves the bonding strength, bioactivity, and biocompatibility of coatings. K E Y W O R D Sbioactivity, biocompatibility, Ca-P coating, laser cladding, microstructure