Anisotropy in the microstructure and mechanical property for the bulk and porous 316L stainless steel fabricated via selective laser melting

Abstract Microstructural anisotropy widely exists in the additive manufactured components during the rapid solidification process, slender columnar grains were formed along the building direction due to the higher thermal gradient caused by the previously deposited layer heat sink. The resistance to deformation along the x-axis or y-axis was confirmed to be larger than that of the z-axis both for the bulk and porous selective laser melted 316L, which was attributed to that most of the grain boundaries were perpendicular to the loading direction for the first two axes. However, the anisotropy in the microstructure and mechanical property can be eliminated after recrystallization.