Influence of process variables on surface roughness of 316L stainless steel parts fabricated via selective laser melting process

Selective laser melting process (SLM) is a metal additive manufacturing technique with excellent design freedom and feasibility. In SLM, a high-energy source is used to melt powder particles into a pattern of successive layers. However, the major challenge associated with the SLM process is that the parts have a high surface roughness (Ra) compared to forming, machining, and rolling processes. In this paper, the core parameters, including scan speed, hatch distance, laser power, and energy density effects discussed as the roughness parameters. The experimental runs were designed based on Taguchi L9 orthogonal array. The results displayed that Ra of samples was largely affected by laser power as compared to scanning speed and hatching spacing. The Ra of samples achieved less at high energy density. In contrast to other surface finishing operations, the polished sample showed the average Ra value of 0.049 µm manufactured at an energy density of 58.83 J/mm3.