Peculiarities of behaviour of Ti–50.7% Ni alloy for suturing of blood vessels

Abstract

Abstract The present work shows that a thermomechanical treatment (TMT) which comprises multipass warm drawing, cold drawing in the last pass and post-deformation annealing (PDA) allows obtaining the highest superelastic functional properties of the Ti–50.7 at.% Ni wire. This material for staples in a form of a 0.30 and 0.315 mm diam. was studied using DSC, shape recovery and mechanical tests. “Know-how” PDA regimes provide the most complete superelastic shape recovery of wire staples for the stapler suturing of blood vessels at the human body temperature. Shape recovery rate of staples under the selected PDA regimes is more than 90% that provides their required functionality. A long-term storage of staples inside the stapler in a straightened condition does not worse their shape recovery rate. The initial cold drawing with 30% strain in the last pass increases the superelastic recovery force by 1.5–2 times as compared to continuous warm drawing. The maximum obtained recovery force value is 6.5 N.