Effect of oxygen content on deformation mode and corrosion behavior in β-type Ti-Mo alloy

• DOI: 10.1016/j.msea.2016.12.062
• Publication Date: 2016-12-15T12:33:25Z
• Authors: Xiaohua Min; Pengfei Bai; Satoshi Emura; Xin ji; Congqian Cheng; Beibei Jiang; Koichi Tsuchiya
• Keywords: 0103 physical sciences; 01 natural sciences

Abstract This study examined microstructural characteristics and mechanical properties in a β-type Ti-15Mo alloy (mass%) with different oxygen contents, and their corrosion behavior in simulated physiological media. With increasing oxygen content from 0.1–0.5%, lattice parameter of parent β-phase increased from X-ray diffraction profiles, and spots of athermal ω-phase became weak and diffuse through transmission electron microscopy observations. {332} twin density decreased with an increase in oxygen content from 0.1–0.3% based on electron backscattered diffraction analyses, and it became almost zero when further increased oxygen content up to 0.5%. The solute oxygen atoms led to both a transition of {332} twinning to dislocation slip and a suppression of β-phase to ω-phase transformation. Room-temperature tensile testing of this alloy with oxygen content ranging from 0.1–0.5%, revealed that yield strength ranged from 420 MPa to 1180 MPa and that uniform elongation ranged from 47–0.2%. The oxygen-added alloys kept a low elastic modulus obtained from stress-strain curves, and exhibited good corrosion resistance in Ringer's solution from open-circuit potential and potentiodynamic polarization measurements. A desirable balance between mechanical properties and corrosion resistance is obtainable in this alloy as biomaterials through utilizing oxygen to control the deformation mode.