A β-type TiNbZr alloy with low modulus and high strength for biomedical applications

The effect of thermo-mechanical treatment on the mechanical properties of a novel beta-type Ti-36Nb-5Zr (wt%) alloy has been investigated. The solution treated alloy consists of beta and alpha '' phases and exhibits a two-stage yielding with a low yield stress (around 100 MPa). After cold rolling at a reduction of 87.5% and subsequent annealing treatment at 698 K for 25 min, a fine microstructure with nanosized alpha precipitates distributed in small beta grains as well as high density of dislocations was obtained to achieve a yield strength of 720 MPa and a ultimate tensile strength of 860 MPa. In spite of the formation of alpha precipitates, the (beta-stabilizers are not enriched in the parent beta matrix due to the short duration and low temperature of the thermal treatment, resulting in a low chemical stability of beta phase. The low stability of beta phase and the small volume fraction of a precipitates produce a low Young's modulus of 48 GPa. Such an excellent combination of low elastic modulus and high strength in mechanical properties indicates great potential for biomedical applications. (C) 2014 Chinese Materials Research Society. Production and hosting by Elsevier B.V. All rights reserved.