Effects of cold deformation on microstructure, texture evolution and mechanical properties of Ti-Nb-Ta-Zr-Fe alloy for biomedical applications

摘要

The effects of cold deformation on the microstructure, texture evolution and mechanical properties of Ti-25Nb-10Ta-lZr-0.2Fe (TNTZF) alloy during cold rolling (CR) were investigated. The results showed that the dominant deformation mechanisms changed from stress-induced a" martensitic transformation and dislocation tangles to twinning, shear bands and nanostructuring with the increase of cold reduction. Meanwhile, the transition from {111}(110) to {111}(112) orientation took place during CR and a dominant {111}(112) texture was obtained after 80% cold deformation. The hardness and strength increased with the increase of cold reduction owing to the effects of the increase of dislocation density and the grain refinement caused by cold deformation. The decrease in Young's modulus after CR is mainly attributed to the stress-induced a" martensitic transformation accompanying with the disappearance of (o phase. The cold deformed TNTZF alloy with reduction of 60% has a great potential to become a new candidate for biomedical applications since it possesses high strength-to-modulus ratio and appropriate plasticity.