Improved elasticity of new Ti-Alloys for Biomedical Applications

The low Young's modulus hasa particular importance in metallic bio-implants for preventing or reducing the occurrence of stress shielding. New concerns on different ways to control the effective elasticity of new Ti-alloys for biomedical applications are discussed in this paper. For this, high Zr-containing Ti67Zr20Nb10Ta3 alloy, with alpha ''+beta phase structure, was designed and the effect of the addition of small amounts of Fe and O were studied. The elastic modulus of the alloys increased with increasing the beta-phase stability in both cold rolled and solution treated conditions. The stress/strain induced phase transformation was observed in the lower beta-phase stability alloys. The cold deformation of these alloys resulted in a change in Young's modulus depending on the degree of beta-phase stability and the measurement direction. The observed anisotropy of elastic modulus in the alloys is related to the texturing in the beta- and alpha ''-phases induced by cold rolling. The non-linear elasticity was observed in both alloys with higher degree in the cold rolled condition. The high elastic admissible strain observed in the present alloys gives a room for developing more mechanically biocompatible alloys as bio-implants. (C) 2014 The Authors.