Influence of MnCO_3 addition on the grain refinement of AZ91 Magnesium alloy

摘要

This article reports the effect of MnCO_3 addition on the grain refinement efficiency of AZ91 magnesium alloy. The results indicate that the addition of MnCO_3 has excellent grain refining efficiency for AZ91 alloy, which is mainly attributed to the Al_4C_3 particles formed in the melt, besides Mn is indispensable to grain refinement in Al-bearing magnesium alloys. There is an optimal addition amount of 0.6% at 740°C and the grain size is reduced from 245 to 91 μm. At the same time, the corrosion resistance performance of MnCO_3-added AZ91 alloy is improved.