Promising composites for wear resistant load-bearing implant applications: Low elastic moduli of β Ti - Nb alloy reinforced with TiC particles and/or TiB whiskers

Despite beta-type Ti alloys achieving a low elastic modulus, metallic implants generally exhibit poor wear resistance. To address this issue, in-situ Ti-based matrix composites (TMCs) are considered due to their strong bonding at the matrix/reinforcement interface. While TiC particles and TiB whiskers are common reinforcements for insitu TMCs, limited research combines their effects with the low elastic modulus of Ti alloys. Here, we present a novel approach using arc-melting on Ti-40Nb alloy with 5 vol% additions of NbC, NbB2, and B4C. Respectively, three TMCs were obtained with the beta-type Ti-Nb matrices reinforced individually with TiC particles, TiB whiskers, and hybridized with both. The produced TMCs exhibited the same passive behavior of the unreinforced Ti-40Nb alloy. However, tribocorrosion resistances were improved, as TMCs achieved nobler potentials during sliding than the unreinforced alloy (-0.5 and -0.9 V, respectively). Notably, the TiB-reinforced and the hybrid reinforced TMCs displayed minimal wear damage, while the TiC-reinforced TMC achieved a remarkable low elastic modulus of approximately 73 GPa. This study introduces promising alternatives for wear-resistant loadbearing implant applications.