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

This study examined microstructural characteristics and mechanical properties in a (beta-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 beta-phase increased from X-ray diffraction profiles, and spots of athermal co-phase became weak and diffuse through transmission electron microscopy observations. {332} < 113 > 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} < 113 > twinning to dislocation slip and a suppression of beta-phase to co-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.