Effect of particle size distribution on the structure and mechanical properties in the process of laser powder bed fusion

Abstract

The paper studies effects of particle size distribution on the structure and mechanical properties of monolithic samples obtained by L-PBF. A powder of 321 austenitic stainless steel of one batch was divided into three fractions 0–20, 20–40, and 0–40 μm. It was established that for narrow fractional powder composition, hardness anisotropy is observed that depends on the building direction, whereas for wide fractional powder composition, hardness anisotropy is practically absent. It was found that the particle size composition of AISI 321 steel powder does not fundamentally affect the morphology of the grain structure. Despite the general preferred orientation of the {101} planes, a weak effect of the powder composition on the crystallites orientation is observed.