The Effect of Sandblasting and Bead Blasting on the Surface Finish of Dry Electrolyte Polishing of Laser Powder Bed Fusion Parts

Selective laser melting is an additive manufacturing process used to produce medical devices; however, current printing methods leave a rough surface finish on manufactured parts. This is undesirable for many applications and post-processing of these devices is necessary to ensure dimensional accuracy and patient comfort. In this study, dry electrochemical polishing was evaluated and the effect that sandblasting and bead blasting have on the polishing time and surface finish was determined. Sandblasting and bead blasting were both effective in reducing the surface roughness of the samples, with both processes reducing the Ra value from about 4.5 to 3 μm. Sandblasting however did leave deep scratches and gauges on the surface as opposed to bead blasting which left a smoother surface texture. After polishing, it was evident that the variation in surface texture between the sandblasted and beadblasted samples influenced the dry electrolyte polishing process’s ability to smooth out surfaces. For cell attachment results, gingival fibroblasts were attached to surfaces with rough and smooth surface finishes. From results obtained, bead blasting showed better results compared to sandblasting as a pre-treatment of samples before polishing using the DLyte system.