Effect of Ca and Y additions on oxidation behavior of magnesium alloys at high temperatures

樊建锋^1,2,3，杨长林⁴，许并社^1,2,3

1. Key laboratory of interface science and engineering in advanced materials,Ministry of education,Taiyuan University of Technology2. Shanxi research center of advanced materials science and technology3. College of Materials Science and Engineering,Taiyuan University of Technology4. State Key Laboratory of Solidification Processing,Northwestern Polytechnical University

摘 要：Oxidation and ignition of magnesium alloys at elevated temperature were successfully retarded by additions of Y and Ca,which could be melted at 1173 K in air without any protection.Thermogravimetric measurements in dry air revealed that the oxidation dynamics curves of Mg-2.5Ca alloy and Mg-3.5Y-0.79Ca alloy at high temperatures followed the parabolic-line law or the cubic-line law.X-ray diffraction（XRD） and scanning electron microscopy（SEM） analysis indicated that the oxide film on the surface of Mg-3.5Y-0.79Ca and Mg-2.5Ca alloys exhibited a duplex structure,which agreed with the results of thermodynamic analysis.By comparison,the ignition-proof effect of the combination addition of Y and Ca was better than that of the single addition of Ca.

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