Investigation of porosity behavior in SLS polyamide-12 samples using ex-situ X-ray computed tomography

Abstract

The paper presents a detailed description of the method of carrying out static tensile tests in ex-situ X-ray computed tomography (XCT) conditions. The study compares samples manufactured with the use of additive technology in two orientations, horizontally and vertically, which correspond to the in-layer and between-layer sintering mechanisms. Both the fracture mechanism and porosity behavior differed significantly for the two manufacturing directions. The conducted analysis made it possible to compare the changes in porosity, the number of pores, and also their diameters and shape before and after the tensile test. This allows for in-depth identification and better understanding of the phenomena occurring during the static tensile test of polyamide-12 samples manufactured using selective laser sintering (SLS) technology.

Influence of the AlSi7Mg0.6 Aluminium Alloy Powder Reuse on the Quality and Mechanical Properties of LPBF Samples

“…Pore sphericity is defined as the aerial ratio of the sphere to the pore where the sphere outlines the pore. The closer the value to one, the higher the pore sphericity is [29]. The results of the data from the individual series and between all the processes coincide with each other.…”

“…Pore sphericity is defined as the aerial ratio of the sphere to the pore where the sphere outlines the pore. The closer the value to one, the higher the pore sphericity is [ 29 ].…”

Characterisation of Process-Induced Defects in Polymeric Strut-Based Lattice Structures Produced by Powder Bed Fusion Additive Manufacturing Process

“…The novelty of this work is the detailed characterisation of voids' shape, such as voids' 3D dimensions, aspect ratio, and orientation, inside the manufactured polymeric lattice structure. As discussed earlier, process-induced voids within the 3D printed samples have typically been represented as spheres in prior research and therefore, the effects of geometric parameters of voids on the mechanical properties of lattice structures under various load scenarios have been rarely investigated [106][107][108]. Although this study solely focuses on characterising void shapes through image processing techniques, the methods of defects characterisation and the subsequent findings will be applied to explore the effects of void shapes on the mechanical properties of additively manufactured lattice structures in future studies.…”