Plasma Polishing as a Post-Processing Method for Surface Improvement in Macro-PBF-LB/M Components

A macro-powder bed fusion of metals using laser beam (PBF-LB/M) setup was utilized in this study to enhance deposition rates using coarser metal powders (0.2 – 1 mm) with a high-power 4 kW laser. Unlike conventional PBF-LB/M, which employs fine powders and thin layers (<100 µm), macro-PBF-LB/M enables rapid fabrication with thicker layers (1 mm) and a wider hatch spacing (3 mm), making it ideal for large-scale manufacturing. However, macro-PBF-LB/M components exhibit poor surface quality, requiring post-processing for smoothness and integrity. Plasma Electrolytic Polishing (PEP) was applied as an environmentally friendly alternative to conventional electrochemical polishing (EP), which uses hazardous acids. The PEP process, combined with initial particle blasting (PB), effectively removed surface oxide layers and significantly improved smoothness over a 64-minute treatment period, resulting in a glossy, uniform finish. Material removal rates were approximately uniform at 0.08 g/min, indicating steady polishing efficiency. These results demonstrate that macro-PBF-LB/M, coupled with PEP, provides a viable high-deposition-rate AM solution with optimized surface quality, making it suitable for robust industrial applications.