Effect of prestrain on martensitic transformation in a Ti46.4Ni47.6Nb6.0 superelastic alloy and its application to medical stents

J Biomed Mater Res B Appl Biomater. 2006 Jan;76(1):179-83. doi: 10.1002/jbm.b.30415.

Abstract

The effect of applied strain on martensitic transformation in a superelastic Ti(46.4)Ni(47.6)Nb(6.0) alloy at room temperature was investigated by tensile tests, differential scanning calorimetry measurements, and X-ray diffraction. Reverse transformation starting (A(s)) and finishing (A(f)) temperatures increased with the application of tensile-strain over 13%, the undeformed specimen showing A(s) = -29.2 degrees C and A(f) = 17.9 degrees C, while the 13% predeformed alloy exhibited A(s) = 37.1 degrees C and A(f) = 40.2 degrees C. Furthermore, the values of the A(s) and A(f) for the predeformed alloy almost recovered to those of the undeformed alloy when heated to about 42 degrees C and then showed superelasticity again at room temperature. This characteristic is significant for application in sensors, actuators, and medical devices. Especially, medical stents with such qualities show promise as a new class of self-expandable stents with both excellent mountability and deliverability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alloys*
  • Materials Testing*
  • Nickel
  • Niobium
  • Stents*
  • Titanium

Substances

  • Alloys
  • Niobium
  • Nickel
  • Titanium