Guide wire and stent
A guide wire that due to its wide elastic region and high Young's modulus, simultaneously has pliability and pushability, and that even when its surface is coated with a plastic material of high melting point, is highly impervious to influences of heat treatment, and that has excellent slidability and excels in weldability between a distal-end-side base material and a proximal-end-side core material. The guide wire has a core material comprising a distal-end-side core material and a proximal-end-side core material.
The distal-end-side core material is made of an iron alloy having shape memorycapability and superelasticity, consisting essentially of two phases of gamma-phase and gamma'-phase and exhibiting, in a thermal hysteresis of martensite transformation and reverse transformation, adifference between reverse transformation completion temperature (Af-point) and martensite transformation starting temperature (Ms-point) of 100 DEG C or below. The proximal-end-side core material ismade of an alloy containing iron and has an elastic modulus higher than that of the distal-end-side core material. The distal-end-side core material and the proximal-end-side core material are weldedtogether.