Ti-Zr-Nb based BCC solid solution alloy containing trace Cu and Ag with low modulus and excellent antibacterial properties

A new series of β-type biomedical alloys Ti₅₀Zr₂₅Nb₂₀Cu_5−xAg_x (x = 0, 1 and 2.5 at%) have been developed. Mechanical properties, antibacterial properties, and biocompatibility of the alloys were systematically investigated. These alloys are body-centered cubic (BCC) phase solid solution with dendritic structure and excellent yield strength and hardness. Meanwhile, the alloys exhibit low Young's modulus (~61 GPa) which is only half of the Ti-6Al-4 V alloy and close to the level of human bone modulus. Due to the increases of the total content of Cu²⁺ and Ag⁺ ions with the Ag partial substitution of Cu, the antibacterial properties of the alloys improves significantly and the antibacterial rate of Ti₅₀Zr₂₅Nb₂₀Cu_2.5Ag_2.5 alloy is above 99.6%. In vitro experiments demonstrate the biocompatibility of Ti₅₀Zr₂₅Nb₂₀Cu_2.5Ag_2.5 alloy is comparable to Ti-6Al-4 V alloy. These β-type Ti₅₀Zr₂₅Nb₂₀Cu_5−xAg_x (x = 0, 1 and 2.5 at%) alloys with superior material mechanical properties, excellent antibacterial properties and good biocompatibility have great potential for antibacterial biomedical implants and associated materials.