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Laser surface polishing of material extrusion additively manufactured 316L stainless steel
Author(s)
Date Issued
February 1, 2026
Type
Article
Abstract
Material extrusion additive manufacturing (MEX) provides a cost-effective pathway for fabricating metallic components; however, its industrial use remains limited by surface defects and high roughness. This study evaluates nanosecond laser polishing (LP) as a post-processing method to improve the surface characteristics of 316L stainless steel produced by Bound Metal Deposition (BMD). The objective is to understand how laser beam diameter, scan speed, and processing atmosphere (air vs. argon) influence surface integrity. Polishing experiments were performed using 50 W and 100 W laser power with beam diameters of 200 and 400 μm at scanning speeds of 100–400 mm/s. Areal roughness (Sa), surface waviness (Wa), surface chemistry, subsurface microstructure, and electrochemical response were systematically characterized. Laser polishing reduced Sa from 2.003 μm to 0.371 μm (81 % reduction) and Wa by up to 43 %. Polishing in argon produced cleaner melt tracks with minimal oxidation, a refined remelted layer, and enhanced passive film formation, leading to improved corrosion resistance (Ecorr improved from −0.466 V to −0.062 V). These findings demonstrate that LP effectively mitigates the surface limitations of BMD-fabricated stainless steel and provide process guidelines for achieving high-quality functional surfaces in MEX metal components.
Citation
Optics and Laser Technology, 194, 2026