Influence of static magnetic field on microstructure and mechanical behavior of selective laser melted AlSi10Mg alloy

Abstract

In this work, the influence of a static magnetic field on the microstructure and mechanical behavior of AlSi10Mg alloy was studied. Our findings show that the applied magnetic field results in increase of the relative density and decrease of cellular dendrite spacing in the processed material. Moreover, the fraction of grains with a columnar morphology decreases and the fraction of equiaxed grains increases with increasing magnetic field intensity. As a result, the AlSi10Mg alloys fabricated via selective laser melted (SLM) with a superimposed magnetic field exhibited both a high ultimate tensile strength and ductility, which are superior to the AlSi10Mg alloys using identical process parameters without magnetic field. Furthermore, the influence of a static magnetic field on the melt pool scale and mushy zone scale was analyzed and simulated numerically. Our results suggest that the decrease pores density may be attributed to magnetic damping of convection and the volume force imposed on the cellular dendrite reaches 105 N/m3, which is sufficient to fracture the columnar grains and refine the cellular dendrite spacing. The present study provides novel insight into the potential of using a superimposed magnetic field during SLM processing and the associated benefits in terms of materials performance.