Effect of Nb Content on Phase Transformation and Comprehensive Properties of TiNb Alloy Coating

As a β phase transformation promoting element of titanium alloy, the Nb element can induce different phase transformations of the alloy, improving the comprehensive properties of the alloy. However, the research on the effect of Nb content on the properties of TiNb alloy coating during laser cladding is not comprehensive. Herein, TixNb (x = 32.5~62.5 wt.%) alloy coatings were prepared by laser cladding technology, and their mechanical properties, corrosion resistance, and biocompatibility were analyzed. The results show that the Nb element promotes the precipitation of different phase components in the phase transformation-induced coating of titanium alloy. The grain refinement during the laser cladding process effectively improves the microhardness of the TiNb alloy coating. At the same time, the wear resistance of the α″ + β dual-phase Ti32.5Nb alloy is enhanced. In addition, with the increase in Nb content, the coating exhibits better corrosion resistance. In vitro cell experiments showed that the TiNb alloy coating had excellent biocompatibility compared to the TC4 substrate. Therefore, the laser-clad TiNb alloy coating has high comprehensive performance and has reference value in the field of biological implantation.