Grain refinement of Mg-alloys by native MgO particles: An overview  

作　　者：Z.Fan F.Gao Y.Wang S.H.Wang J.B.Patel 

机构地区：[1]Brunel Centre for Advanced Solidification Technology(BCAST),Brunel University London,Uxbridge,UB83PH,UK

出　　处：《Journal of Magnesium and Alloys》2022年第11期2919-2945,共27页镁合金学报（英文）

基　　金：the EPSRC (UK) under grant number EP/N007638/1。

摘　　要：A fine and equiaxed solidification process delivers multidimensional benefits to Mg-alloys, such as improved castability, reduced casting defects, enhanced mechanical properties, increased corrosion resistance and potential for increased recycled contents. Despite extensive research on grain refinement of Mg-alloys in the last few decades, currently, there is no effective grain refiner available for refining Mg-Al alloys, and our current understanding of grain refining mechanisms is not adequate to facilitate the development of effective grain refiners.Under the EPSRC(UK) Li ME Hub’s research program, substantial advances have been made in understanding the early stages of solidification covering prenucleation, heterogeneous nucleation, grain initiation and grain refinement. In this paper, we provide a comprehensive overview of grain refinement of Mg-alloys by native MgO particles. We show that native MgO particles can be made available for effective grain refinement of Mg-alloys by intensive melt shearing regardless of the alloy compositions. More importantly, we demonstrate that(1) the addition of more potent exogenous particles will not be more effective than native MgO;and(2) MgO particles are difficult to be made more impotent for grain refinement through promoting explosive grain initiation. We suggest that the most effective approach to grain refinement of Mg-alloys is to make more native MgO particles available for grain refinement through dispersion, such as by intensive melt shearing.

关 键 词：Mg-alloys Grain refinement Magnesia(MgO) NUCLEATION Grain initiation 

分 类 号：TG146.22[一般工业技术—材料科学与工程]