Mechanical Properties and Biocompatibilities of Zr-Nb System Alloys with Different Nb Contents for Biomedical Applications

The microstructures, mechanical properties, and biocompatibilities of as-solutionized Zr-Nb system alloys with different Nb contents for biomedical applications were investigated. The microstructures of Zr-5 mass%Nb, Zr-10 mass%Nb, and Zr-20 mass%Nb alloys subjected to solution treatment (ST) consist of alpha', omega, and beta phases while the microstructure of Zr-30 mass%Nb alloy subjected to ST consists of almost all single beta phase. Young's modulus of Zr-20 mass%Nb alloy shows the lowest value of 63 GPa among the others alloys although the tensile strength and 0.2% proof stress decrease because of decrease in volume fraction of omega phase while Zr-10 mass%Nb alloy with a large amount of omega phase shows the highest values of Young's modulus, tensile strength, and 0.2% proof stress. The elongations of Zr-20 mass%Nb and Zr-30 mass%Nb alloys show relatively high values of 22% and 24%, respectively. The cell viability and bone-bonding characteristics of Zr-Nb system alloys are improved with increasing Nb content. Therefore, it is considered that Zr-Nb alloys have relatively high biocompatibility and belong to bio-inert metallic biomaterial.