Development of Ti-26Nb-1.2TiC shape memory composite for biomedical applications

Ti-Nb alloys have great potential in biomedical applications as bone-implant materials due to their low elastic modulus, superelasticity, high corrosion resistance, and good biocompatibility. However, the low yield strength and poor superelasticity of Ti-Nb alloys restrict their practical clinical applications. Here, we report the mechanical properties and superelasticity, corrosion behavior, and biocompatibility of a Ti-26 at.% Nb-1.2 vol.% TiC (Ti-26Nb-1.2TiC) shape memory composite (SMC) prepared by vacuum arc melting and hot rolling. The yield strength, critical stress for inducing martensitic transformation, and elongation of the Ti-26Nb-1.2TiC SMC and a Ti-26Nb alloy were 460 and 337 MPa, 251 and 115 MPa, and 27.2% and 24.1%, respectively. The recovery rate of the SMC under 4% pre-strain reached 91.4%, which was 1.2 times that of the Ti-26Nb. Electrochemical tests in Hanks' solution revealed that the corrosion current density, passive current density, and corrosion rate of the SMC were lower than those of the Ti-26Nb. Both the Ti-26Nb alloy and Ti-26Nb-1.2TiC SMC showed good cell viability with grade 0 cytotoxicity in relation to MG-63 osteosarcoma cells.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.