Microstructural defects induced by stereolithography and related compressive behaviour of polymers

The goal of this work is to discover the defects induced by 3D printing of porous polymeric blocks using stereolithography and any related compressive behaviour. Processing of polymeric blocks containing varied porosity contents in the range 0–60% is performed. X-ray micro-tomography is used to assess the microstructural details of the polymeric blocks. Compression testing is realized up to densification on all orthogonal faces. Mechanical characterization of the blocks shows the typical behaviour of a cellular material and limited anisotropy effect related to building direction. Defects such as trapped resin, altered support structure and unbuilt porosities are quantified. This study concludes that the design of airy structures needs to exclude any form of closed porosity to enable processing using stereolithography.