The effect of Ca addition on viscosity and electrochemical properties of Mg-alloys produced by casting

Summary form only given. The composition of different Mg alloys is known to affect their current capacity, potential, and anode efficiency. Many alloying elements have been used in attempts to improve the electrochemical properties of magnesium anodes. Significant improvements of electrochemical properties have been achieved by controlling the adverse effects of impurity elements such as Fe, Ni, Cu with alloying elements. Out of many elements, Ca is considered as a very effective element that can improve the electrochemical properties of Mg-alloys because of its relatively low potential in comparison with specified elements such as Mn, Al, Zn in high Mn alloys or AZ63 alloys with the effect of grain refining. Ca has recently been used as a common inhibitor for the ignition of molten Mg alloys. However, the viscosity of pure Mg is markedly increased with increasing Ca content. Ca is responsible for making the casting of Mg alloys from Mg melt difficult at desirable pouring temperatures. In the present study, the effect of Ca addition on the viscosity and electrochemical properties of Mg-Ca alloys is investigated. Viscosity as well as electrochemical data will be correlated with chemical composition of impurities, and the microstructural change before and after Ca is added.