Microstructural and mechanical properties of novel β-type Ti–Nb–Ni alloys containing a second phase

Abstract

AbstractThe microstructure and mechanical properties of novel β-type Ti74-xNb26Nix (x = 4, 8, 12, 16, 20, and 24 at.%) alloys with a low Young's modulus and containing different amounts of a second phase (Ti2Ni and Ni3Nb) were investigated. The experimental results show that the relative volume fractions of Ti2Ni phase in the Ti–Nb–Ni alloys increased with increasing Ni content. The mechanical properties of Ti–Nb–Ni alloys varied with the amount of second phase. Ti70Nb26Ni4, Ti66Nb26Ni8, and Ti62Nb26Ni12 alloys containing a small amount of Ti2Ni phase exhibited a higher plastic strain; however, Ti58Nb26Ni16, Ti54Nb26 · Ni20, and Ti50Nb26Ni24 alloys containing a large amount of Ti2Ni phase and a small amount of Ni3Nb phase exhibited a small plastic strain. The increase in strength and decrease in plasticity of alloys can be mainly attributed to the increase in high-strength brittle Ti2Ni phase and grain refining of the β-phase matrix. In addition, Ti50Nb26Ni24 alloy with a low Young's modulus has a high yield strength and elastic energy; this has potential application as biomedical and functional materials.