Grain refining mechanisms in magnesium alloys - An overview

Abstract

The literature on mechanisms of grain refinement in magnesium alloys is reviewed with regard to two broad groups of alloys: aluminium-bearing and aluminium-free alloys. While a low level zirconium addition significantly reduces the grain size of the aluminium-free alloys, the understanding of mechanisms of grain refinement in aluminium-bearing alloys is poor and in some cases probably confusing due to the interaction between impurity elements and aluminium in affecting the potency of nucleant particles. Mechanisms of grain refinement in magnesium alloys are dealt based on the experimental results in conjunction with microstructural observations. Informations revealed by this approach identify new directions for further research to focus on obtaining an improved understanding of the detailed mechanisms of grain refinement in magnesium alloys.