Patent ID: 8034101

Claim:
An implant device for medical application being used by being implanted in a living body, comprising a principal part formed by a magnesium-based biodegradable metallic material consisting of (i) Mg at a concentration equal to or more than 93.5 atomic %, (ii) one element having a larger metallic radius than that of magnesium, as a secondary composition, at a concentration equal to or less than ⅓ of its solubility limit to magnesium and its concentration unevenly distributed at a grain boundary is controlled to be a concentration equal to or more than 1.5 times of an average concentration in the grain, and (iii) inevitable impurities at a concentration equal to or less than 0.05 atomic %, and no precipitates or intermetallic compounds, and its average grain size is equal to or less than ¼ of a minimum part of a structural component.