Optimisation of surface roughness of FDM fabricated parts: application of definitive screening design and genetic algorithm techniques

This study presents an experimental investigation on the impact of variations in various fused deposition modelling (FDM) process parameters such as layer thickness, build orientation, raster angle, part raster width, raster to raster air gap, number of contours, contour width and part shrinkage factors on the top surface roughness of FDM printed poly-carbonate parts. To meet the study objective, definitive screening design (DSD) and ANOVA techniques were used to develop a predictive model for establishment of a functional relationship between the selected process parameters and part surface roughness. Thereafter, the predictive model was validated and optimised using genetic algorithm (GA) technique. The comparison of optimal and default process parameter settings showed an improvement in surface roughness of 60.9%. The proposed combined DSD-GA approach can assist practitioners in fabrication of various industrial products to uplift the additive manufacturing (AM) sector.