Effect of tantalum content on structure, mechanical and biochemical properties of ti-20nb-xta (x = 7.5; 10.0% (at.)) alloys for medical implants

The structure, phase composition, mechanical properties and biocompatibility of medical alloys Ti-20Nb-7.5Ta and Ti-20Nb-10Ta% (at.) were studied after warm rolling to a thickness of 1.5 mm and subsequent quenching at 600 and 800 °C. The alloys consist mainly of the β-phase, while the alloy with 7.5% (at.) Ta also contains traces of α′ / α′′-phases. Quenching from 600 °C reduces the tensile strength of the alloys to 526-528 MPa, and quenching from 800 °C does to 499-506 MPa. Relative elongation of alloys after rolling is 9.7-9.8%. It increases to 13.3-13.5% after quenching from 600 °C and to 15.5-19.4% after quenching from 800 °C. The tantalum content affects the manifestation of the superelasticity effect: for the Ti-20Nb-7.5Ta alloy in the quenched state, the superelastic deformation is ≈1.5%, and for the Ti-20Nb-10Ta alloy this effect is weakly expressed. Both alloys do not have a toxic effect on human neuroblastoma SH-SY5Y cells. The most promising for use in implants is the Ti-20Nb-7.5Ta alloy in the quenched state.