Investigation of Manufacturing 316L Stainless Steel Closed Impeller Using Laser Powder Bed Fusion

Abstract

The manufacturing of closed impellers via Laser Powder Bed Fusion technology entails inherent complexities, demanding meticulous attention to support structure design, determination of building angle, and down-skin energy density to ensure successful production. This study explores the use of stainless steel 316L in fabricating closed impellers using LPBF. The aim is to investigate the impact of process parameters and building angles on impeller fabrication quality. In addition to studying the effect of energy density on the surface roughness and hardness values of the impeller. The investigation examines building angles of 0˚, 30˚, and 90˚ for a closed impeller, revealing that a 30˚ building angle yields successful printed parts. Moreover, to achieve defect-free closed impellers, it is imperative to maintain down-skin energy density between 80% and 100% of in-skin energy density. The maximum hardness and minimum surface roughness were recorded at 233 HV and 12.79 µm, respectively, when the energy density was 41.66 J/mm³ and 55.55 J/mm³ respectively.  The novelty of this study lies in the fabrication of closed impellers using stainless steel 316L through laser powder bed fusion.