Effects of minor Ca on as-cast microstructures and mechanical properties of Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys
(1. Key Laboratory of Manufacture and Test Techniques for Automobile Parts, Ministry of Education,
Chongqing University of Technology, Chongqing 400054, China;
2. Materials Science and Engineering College, Chongqing University of Technology, Chongqing 400050, China;
3. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030, China)
Chongqing University of Technology, Chongqing 400054, China;
2. Materials Science and Engineering College, Chongqing University of Technology, Chongqing 400050, China;
3. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030, China)
Abstract: The effects of the addition of 0.6% Ca (mass fraction) on the as-cast microstructure and mechanical properties of the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc magnesium alloys were investigated and compared by optical microscopy and scanning electron microscopy, differential scanning calorimetry analysis, and tensile and creep tests. The results indicate that the addition of 0.6% Ca to the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys can refine the grains of the two alloys. At the same time, the addition of 0.6% Ca to the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys can effectively improve the tensile properties of the two alloys. In addition, the addition of 0.6% Ca can also improve the creep properties of the Mg-3Ce-1.2Mn-0.9Sc alloy but is not beneficial to the creep properties of the Mg-4Y-1.2Mn-0.9Sc alloy. The different effects of minor Ca on the creep properties of the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys are possibly related to the difference in the solid solubilities of Ce and Y in Mg.
Key words: magnesium alloys; Mg-RE-Mn-Sc alloys; Ca addition