Surface quality remains one of the biggest problems when manufacturing products using selective laser sintering (SLS). The SLS is an additive manufacturing device or a 3D Printer. It uses a laser to melt a thin layer of polymer powder then deposits another layer of powder and melts the next layer, allowing complex geometries to be formed. Several experiments are being performed using different SLS input variables in order to manufacture samples with different surface characteristics. The effect of virgin or recycled powder, the laser power utilized, the roller speed, and the space between passes of the laser are studied and related to surface defects. A metrology system with a 4th axis for rotating and imaging tools system is utilized to analyze samples.
When analyzing surface quality, the first analysis that must be done is determining the ‘true area’, which in contrast to the ‘projected area’, it includes all asperities, whether they are peaks or valleys. The ‘projected area’ is the sampling area scanned by the metrology system. The ratio of these two areas known as the ‘area ratio’, is closely related to friction properties of the surface. Two important properties are then computed to assess the surface texture: average surface roughness (Ra) and root mean square roughness (Rrms).
Dimensional scans of SLS parts from the Alicona