Heat treatment processes and mechanical properties of new beta-type biomedical Ti-29Nb-13Ta-4.6Zr alloy

Practical size ingot of new beta-type titanium alloy Ti-29Nb-13Ta-4.6Zr. wh ich was composed of non-toxic elements of Nb. Ta and Zr, with lower modulus of elasticity, high strength and excellent biocompatibility was tried to b e fabricated. Then the heat treatment processes of the alloy, which gave a good balance of strength, ductility and modulus of elasticity, were investi gated in this study. Practical size ingot of Ti-29Nb-13Ta-4.6Zr with a weight of 17 kg has been successfully fabricated. The distribution of alloying elements was homogene ous through the ingot. The practical size ingot can be easily hot forged an d cold rolled by a total reduction of 98%. Ti-29Nb-13Ta-4.6Zr which was aged after cold rolling indicates higher stren gth and lower elongation as compared with those of the alloy aged after sol ution treatment. In the aging temperature range between 598K and 648K, the alloy indicates relatively higher strength and lower elongation. The precip itation of omega phase increases tensile strength anti decreases elongation in the alloy aged between 598K and 643K after solution treatment. In the a ging temperature above 673K, the precipitation of alpha phase increases ten sile strength and elongation in the alloy aged after solution treatment. Ne w alloy has excellent strength ductility relationship when aging temperatur e was above 673K.