Comparison of different post processing technologies for SLM generated 3161 steel parts

Purpose - The purpose of this paper is to compare different post processing techniques for improving the high surface roughness (SR) characteristic of parts generated by selected laser melting (SLM). Design/methodology/approach - Test parts were built by SLM and their surface was characterized via SEM and optical measurements. The surface of the as-generated parts was then modified by grinding, sand blasting and electrolytic and plasma polishing to reduce the SR. Findings - The change of the SR after the different surface treatments was quantified and compared. The effectiveness and usability of the post processing techniques and their combinations were determined. The results indicate that some of the post processes are only usable for simple structures. Research limitations/implications - The amount of abrasion induced by the different surface treatments was not quantified. A major focus of future work should deal with this issue. Practical implications - The surface quality of parts with simple geometry can be enhanced by simple methods such as grinding. Complex parts need more advanced techniques, such as electrolytic polishing. Originality/value - The effect of different post processing techniques for improving the surface roughness of SLM-generated parts has been analyzed for the first time. This paper can help to improve the SR of parts produced by SLM.