| 摘要 |
<p>This invention is a population of radially expansible stents (14) having substantially uniform characteristics and a method for producing a population of stents with predetermined, uniform thermal and mechanical properties. The process includes deforming the stents into a hollow tube having a desired diameter, and heating the stents sufficiently to homogenize the microstructure of the alloy, thereby increasing stents' ductility to about 40 %-50 % strain. After heating, the stents are shape-set at a desired diameter at an Af temperature below body temperature. The high ductility and homogenized microstructure increases the fatigue life and improves the uniformity of the population of stents. In addition, the method of the present invention allows the Af temperature to be shifted up or down during processing, providing more precise control of the final Af temperature.</p> |
