Material removal characteristics of various surface features on selective laser melted 316L stainless steel during electropolishing

This study aims to establish the relationship between material removal characteristics and various surface features on selective laser melted 316L stainless steel after electropolishing (EP). Morphology and roughness were characterized on top, face up, side and face down surfaces of 316L stainless steel samples prepared by selective laser melting (SLM). Three types of un-sintered powders and two types of sintered area were categorized and further investigated based on the differences of morphology, microstructure and location. Material removal mechanism of each surface feature was also studied based on experimental and simulation results. Impacts of these surface features on the reduction of roughness during EP were thus discussed. The study reveals that different microstructures and feature locations lead to diverse material removal behaviors during EP process. Understanding the characteristics of un-sintered powders and sintered area on SLM surfaces is crucial in achieving satisfactory surface finish in EP.