Evaluation of Fused Deposition Modelling process parameters influence on the porosity of printed parts

Fused Deposition Modelling (FDM) is an additive manufacturing technology that is rapidly gaining popularity due to its ability to produce complex shaped parts in a short time. However, parts produced by means of FDM have porosity that results from the printing process. The mechanical properties of printed parts depend on the FDM process parameters and porosity. This study investigates the effect of FDM process parameters on the porosity of FDM parts. The results of the study show that properly selected FDM process parameters can significantly minimize the percentage of part porosity. The effect of FDM process parameters on porosity was determined by analyzing nine process variables: layer height, extrusion temperature, printing speed, extrusion multiplier, bed temperature, infill pattern, deposited strand width, number of shells, number of solid top and bottom layers. The percentage of samples porosity was measured by means of the hydrostatic weighing method. Using the analysis of variance, statistically significant factors and their combinations affecting the percentage of parts porosity were determined. It was shown that the extrusion multiplier had the greatest influence on the percentage of parts porosity. A significant contribution to the formation of porosity was made by the infill pattern, layer heights, printing speed, number of shells, number of solid top and bottom layers and their interaction. A regression model has been developed that allows predicting the porosity of parts achieved by different combinations of FDM process parameters.