MICRO-GEOMETRIC STRUCTURAL ANALYSIS OF FDM 3D PRINTED PARTS USING COMPUTER TOMOGRAPH IMAGING

Abstract

This paper presents a structural and micro-geometric analysis of Fused Deposition Modeling 3D printed parts using Computed Tomography imaging as a non-destructive evaluation tool. Samples were fabricated using a Prusa MK4S, with key parameters such as wall line count, wall thickness, and infill density, systematically varied. The 3D geometry and internal structure of the printed parts were scanned using an industrial CT system, a Bruker SkyScan 1272. Based on the CT results, the actual density of each sample was calculated and compared with the values provided by the manufacturer. An ANOVA statistical analysis was performed to evaluate the influence of the FDM parameters that were previously varied on the measured density variability. Additionally, qualitative inspection of the CT data enabled identification of characteristic manufacturing defects, including deformations on the interface between rectangular and cylindrical surfaces, weak layer adhesion between macro-volumes, and filament detachment at sharp toolpath transitions (≥45°). These findings provide critical insights into the microstructural fidelity of FDM processes and support future optimization strategies for additive manufacturing reliability.