Permeability and Porosity Analysis of a Unique Porous Media Obtained by Bead Width Variation in a MEX Filling Strategy

Abstract

Additive manufacturing (AM) allows the production of the internal structure of porous media (PM) with porosity and permeability tailored for a specific application. Material extrusion (MEX) AM enables the fabrication of a lattice-type porous structure by varying process parameters, usually applying the zigzag raster filling strategy. In a recent study, a Variable Bead Width Porous Filling (VBWPF) strategy was proposed, which generates pores by changing the printing speed during filament deposition and resulting in a unique porous structure with less pore interconnectivity. Specific pores’ dimensions and distribution on the layer can be obtained with the strategy’s parameters. In this work, different configurations of the VBWPF strategy were produced, and their porosity and permeability were measured experimentally. A PM with traditional raster filling (lattice structure) was also printed and measured for comparison. The porous structures of different VBWPF configurations were analyzed with micro-computed tomography (µCT). The results showed that VBWPF parameters were able to modify the porous structure obtained, changing the porosity and permeability of the PM. The PM produced exhibited 27% lower porosity and 55% lower permeability than the traditional raster filling PM with similar pore widths. These unique characteristics open up the field for applications of PM obtained through AM.