High Temperature Oxidation Behavior of Mg-5% Ca-1% Zn Alloys |
Kwon Yong Ji, Dong Bok Lee |
School of Advanced Materials Science & Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea |
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Received: 14 October 2015; Accepted: 9 April 2016. Published online: 5 September 2016. |
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ABSTRACT |
Pure Mg, Mg-5wt%Ca, and Mg-5wt%Ca-1wt%Zn alloys were cast, and their high-temperature oxidation behavior was investigated to determine the roles of Ca and Zn in oxidation. Ca and Zn additions refined the microstructure by formation of Mg2Ca and Ca2Mg6Zn3, respectively, at grain boundaries. Ca increased the oxidation resistance by forming a thin, compact CaO scale on the surface. However, Zn decreased the oxidation resistance because of the formation of Ca2Mg6Zn3, which increased the MgO-forming tendency. |
Keywords:
alloys, casting, oxidation, scanning electron microscopy (SEM), Mg-Ca-Zn alloys |
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