Experimental study on enhancing surface integrity and corrosion resistance in additively manufactured 316L stainless steel through vibratory finishing technique

Abstract

This study explores the impact of vibratory finishing (VF) on the surface characteristics and corrosion resistance of stainless steel 316L produced via selective laser melting (SLM). SLM, a common technique in aerospace and biomedical industries, often struggles to achieve optimal corrosion resistance in stainless steel parts. VF, a widely used post-processing method, was evaluated using different media shapes and processing times. The findings showed that cylindrical media over a 12-h VF process resulted in significant edge rounding, surface smoothing, and a weight reduction of 0.178 g, while triangular media produced a minimal weight change, decreasing from 9.315 to 9.230 g. A significant improvement in surface roughness (Ra) was observed, with up to a 90% reduction, reaching a minimum Ra value of 0.95 μm. Additionally, microhardness improved by 8.1%, reaching 225 HV. The best corrosion resistance was achieved using triangular media, where the corrosion rate dropped from 82.5 µm/year to 7.45 µm/year after 12 h of VF. The study concludes that prolonged VF treatments, especially with cylindrical media, effectively enhance the surface integrity and corrosion resistance of SLM-produced stainless steel 316L components.