| 摘要 |
Provided are a stent which has sufficient strength, is easily reduced in diameter to facilitate insertion of the stent into a tube, and can be smoothly expanded from inside the tube and a process for producing the stent. This stent (10) is a self-expandable stent constituted of an Ni-Ti base alloy or Co-Cr base alloy and formed into a cylindrical shape with mesh openings. The stent has been configured so that the Af point is 22-26°C, the stress-displacement curve has a yield point, and the crystal grains in a cross-section of the stent have an average cross-sectional area, as determined by the area fraction method, of 0.2-50 µm 2 . The stent can be produced by inserting a core bar (22) into a cylindrical stent base (20), forming mesh openings with laser light, subsequently removing the core bar from the stent base, expanding the stent base to a given diameter in an atmosphere having a temperature of 350°C or lower, and then subjecting the expanded stent base to a heat treatment at 400-600°C for 5-60 minutes to regulate the Af point to 22 to 26°C. |
