Improved mechanical and biological properties of Ti-13Nb-13Zr alloy treated by surface ultrasonic rolling and copper infiltration

Abstract

As a novel near β titanium alloy with low modulus and outstanding biocompatibility, Ti-13Nb-13Zr (TNZ) alloy shows great potential for orthopedic implants. However, the poor wear resistance and biological inertness of TNZ alloy have greatly restricted its further application in hard tissue replacement. In this study, a copperized TNZ (Cu/TNZ) alloy with typical gradient nano-structure (GNS) was fabricated using surface ultrasonic rolling treatment (SURT) followed by copper infiltration. The surface microhardness as well as friction and wear properties of GNS Cu/TNZ alloy were strikingly improved in comparison to those of coarse-grained (CG) TNZ alloy and GNS TNZ alloy. The corrosion resistance of GNS Cu/TNZ alloy was also substantively enhanced, which was mainly ascribed to the formation of passive film caused by gain refinement and copperizing process. Meanwhile, the rapid release of Cu2+ from the surface layer endowed GNS Cu/TNZ alloy with excellent antibacterial activity. Moreover, the cell proliferation on GNS Cu/TNZ alloy was comparable with those of TNZ alloy and GNS TNZ alloy, showing no cytotoxicity. The striking enhanced mechanical performance and biological properties of GNS Cu/TNZ alloy owing to grain refinement and copper infiltration in the surface layer make it a promising candidate for clinical dental and orthopedic implants.