Enhancing biocompatibility, mechanical properties, and corrosion resistance of laser cladding β-TiNb coatings

Abstract

β-type TiNb biomedical alloys have received quite significant attention rooted in their excellent comprehensive performance. Nevertheless, their practical application is hampered by relatively poor performance and biological toxicity. Herein, TixNb alloy coatings were fabricated on the surface of Ti6Al4V (TC4) by laser cladding to evade the property-toxicity trade-off. Biocompatibility and mechanical properties, as well as the corrosion resistance of the TixNb alloy coatings, were discussed. The results show that the microstructure is composed of β grains and a small amount of the α″ martensite phase uniformly precipitated around them. The rapid melting process of laser cladding promotes the formation of the β phase, which improves the microhardness and wear resistance of the coating. However, the corrosion resistance was significantly improved due to the formation of the densification and stabilization of the passive films formed on the coating’s surface. Benefiting from the superior wettability and the biologically active sites of Ti and Nb on the alloy surface, MG-63 cells adhered to the coating’s surfaces in spindle shape and proliferated rapidly in cell experiments, denoting that the coatings have better biocompatibility than TC4. Hereby, the obtained TixNb laser cladding coatings with excellent mechanical properties and biocompatibility have extensive application prospects in the field of orthopedic biomaterials.