J111016 X線照射による表面改質を施した純マグネシウムの腐食現象

抄録

Magnesium (Mg) has the lowest negative standard electrode potential (-2.363V) among industrial metals. This means that corrosion phenomena is easily occurred by a galvanic cell formed at the interface two materials when Mg specimens contact with the other metals. The conventional methods to improve corrosion resistance of Mg alloys are anodic oxide film formation and chemical conversion treatment. However, these methods are expensive and Mg products treated by these methods are hard to recycle. In this study, advanced corrosion protection of pure Mg by electron excitation was investigated. Pure Mg surface was modified by X-ray irradiation under atmospheric environment. XPS analysis indicated MgO layer was formed at the surface of pure Mg specimen. Cross-sectional observation by TEM showed the MgO layer was dense compared to the natural oxidation coating films. For the outermost surface of the MgO samples were functioning as a protective film, X-ray irradiated Mg showed good corrosion resistance and lower surface potential than that of the as-polished Mg.