The research on the effect of MgCO3on the grain refinement in AZ31 magnesium alloy

Abstract

The effect of MgCO3 addition on the as-cast microstructure of AZ31 magnesium alloy has been widely investigated. The results show that the average grain size of the α-Mg grain in AZ31 magnesium alloy decreases from about 570 μm to 100 μm by the addition of 0.6 wt.% MgCO3 as gain refiner at 760°C. Based on the analysis of EDS, theoretical calculation of Ebind and Gibbs free energy, we esteem that grain refiner mechanism is mainly attributed to the generation of Al4C 3, which can be serviced as nucleation site and restrain grain boundary from growing and transferring. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.