Investigating the Surface Roughness of SLS Fabricated Glass-Filled Polyamide Parts Using Response Surface Methodology

Abstract

Selective laser sintering (SLS) is an additive manufacturing process, which has become popular for the production of full functional end-user parts as well as prototypes. Presently, many sectors particularly aerospace, automotive and biomedical are using 3D solid models (prototypes) for visualization, kinematic testing or to fulfil other functional demands. Therefore, SLS parts should have good surface quality (i.e. surface roughness) to fulfil the demands of these sectors. Surface roughness of the SLS fabricated parts relies on the various input process parameters. Hence, this study investigates the influence of key contributing factors (i.e. bed temperature, laser power, scan speed, scan spacing and scan length) on the surface roughness of glass-filled polyamide parts. Five factors, three-level, and face-centred central composite design of experiment were used to collect data, and response surface methodology was employed to investigate the effects and interactions of selected input process parameters. It has been found that scan spacing followed by laser power is the most significant factor, which contributes the most to improve surface roughness. Furthermore, the optimum values of different parameters were obtained and verified by conducting confirmation experiments.