Использование эффекта сверхэластичности при разработке внутрисосудистых медицинских имплантатов из сплавов на основе никелида титана

The urgency of the discussed issue is caused by the need to work out new types of industrial intravascular implants from nickel-titanium based alloys. The main aim of the study: analysing a structurally-phase state and characteristics of the martensitic transformations effect in medical nickel-titanium based alloys to implementation of superelasticity effect and by the example of a concrete alloy to determine experimentally an optimum regime of its heat treatment for the directed regulating of the structurally-phase state providing high extent of shape recovery as a result of superelasticity effect. The methods used in the study: thermal resistivity measurements to determine martensite transformation temperatures; torsion deformation method by an inverted torsion pendulum with loading and unloading of samples for measurements of the superelasticity effect and shape recovery parameter. The results: The authors have analyzed the conditions of effect superelasticity developing in nickel-titanium based alloys by martensitic transformations; determined the magnitude and temperature intervals of developing superelasticity effect, shape restoration extent, required for using nickel-titanium based alloys as the materials for manufacturing intravascular implants. It is shown, that for medical nickel-titanium based alloys the required characteristics of implants are attained at heat treatment for implant shape assignment during 15…30 minutes at (500±10) °С.