Oxidation behavior and improvement in nonflammability of LPSO-type Mg–Zn–Y–Sr alloy

Mg₉₇Zn₁Y₂ alloys with high ignition temperatures were developed by adding Sr. The addition of Sr resulted in the formation of a uniform and thin Y₂O₃ film. Mg–Zn–Y alloys containing at least 0.25 at.% Sr exhibited ignition temperatures of 1270–1320 K. As a result of EDS measurement, Sr was found to be concentrated in the Y₂O₃ film. In addition, a mixed film of MgO and SrO formed on the outer layer in the 1.5 at.% Sr-containing Mg₉₇Zn₁Y₂ alloy. These findings suggest that the uniform and thin Y₂O₃ film that maintains high soundness at high temperatures was formed owing to valence control and the formation of a protective outer oxide film.