Creation of Superelastic Functional Properties in a Ti-50.7%Ni Wire for the Stapler Suturing of Blood Vessels
| Periodical | Advances in Science and Technology (Volume 76) |
|---|---|
| Main Theme | 5th FORUM ON NEW MATERIALS PART E |
| Edited by | Pietro VINCENZINI, John A. JANSEN, Kazuhiko ISHIHARA and Thomas J. WEBSTER |
| Pages | 253-258 |
| DOI | 10.4028/www.scientific.net/AST.76.253 |
| Citation | I. Khmelevskaya et al., 2010, Advances in Science and Technology, 76, 253 |
| Online since | October, 2010 |
| Authors | I. Khmelevskaya, M. Soutorine, S. Prokoskin, E. Ryklina |
| Keywords | Functional Property, Stapler, Superelastic Staple, Thermomechanical Treatment (TMT) |
| Price | US$ 28,- |
The technique of aorta-coronary shunting offered by Dr. M. Soutorine by means of the original stapler developed by "Endogene" allows suturing blood vessels by superelastic Тi-Ni staples on «working heart» (without heart switching-off). The material for staples is a 0.30 and 0.315 mm diam. wire which was studied by DSC, shape recovery and mechanical tests. Thermomechanical treatment (TMT) comprised warm drawing, low- temperature (LTMT) by cold drawing with 25-30% strain in the last pass and following post-deformation annealing (PDA). LTMT leads to increasing of yield stress in comparison with warm drawing. Treatment of wire under LTMT+PDA allows obtaining the highest characteristics of functional properties of the wire. The difference between “dislocation” and “transformation” yield stresses Δ=900 MPa. Critical stress of superelastic recovery after TMT on the average is 1.5-2 times higher in comparison with warm drawing. The maximum completely recoverable strain r,1max=6.5%. The maximum obtained force value of staples is РrSE=6.5 Н. The shape recovery rate of staples was 85-97 % that provided its functionality. Storage in the stapler in straightened condition within 1 month does not worse the staples.