This experimental study aims to investigate the effect of process parameters like print orientation and layer height on the printed bead interactions and voids produced during an additive manufacturing (AM) process, more specifically material extrusion aka fused filament fabrication (FFF). Additionally, the study also investigates their effect on both the mechanical response and failure behaviour of the FFF-printed specimens subjected to different types of loading such as tensile, compressive and shear loading. Specimens are printed with a total of three print orientations (0, 0/90, and ± 45°) and three layer heights (50 μm, 125 μm, and 200 μm). X-ray computed tomography (CT) is employed to gain insights into the effects of printing process parameters on void formations, their size, shape and distribution in the FFF-printed specimens. During the loading event, full-field strain distribution and out-of-plane deflection of the specimens are obtained by utilizing the 3D digital image correlation (DIC) technique. The fractured specimens under tensile loading are further examined for the (3D) profiles of fractured surfaces and related fracture-causing mechanisms utilizing a high-resolution digital stereomicroscope. In addition, X-ray CT is also employed again to gain insights into the effects of loading type on the voids in deformed specimens. Voids and internal bead structures of both virgin and deformed specimens are compared to understand the deformation and failure mechanism of 3D printed specimens under various loading conditions. The shape, size, and distribution of the voids in the FDM printed specimens are observed to be highly dependent on the layer height and the print layout of the specimens. The content of voids is observed to be lowest in [0]2N-printed specimens (3.54–7.69% for different layer heights), which increased approximately twice for [0/90]N (7.69–13.61%) and approximately 2.5–3 times for [± 45]N (10.44–14.66%). In addition, void content in the [0]2N-printed specimens is observed to be the most sensitive to changes in layer height (approximately 117% variation between 50 and 200 µm), whereas least sensitive for [± 45]N-printed specimens (approximately 40% variation between 50 and 200 µm). Furthermore, the mechanical response and failure behaviour of the specimens are also observed to be highly dependent on the considered printing process parameters owing to the changes in the void content and their effects on different print configurations and loading types.

Effects of voids on mechanical response and failure behaviour of additively manufactured Onyx

期刊论文
发表日期：

2025年5月9日

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Kuldeep Yadav,
Vikrant Tiwari

摘要

This experimental study aims to investigate the effect of process parameters like print orientation and layer height on the printed bead interactions and voids produced during an additive manufacturing (AM) process, more specifically material extrusion aka fused filament fabrication (FFF). Additionally, the study also investigates their effect on both the mechanical response and failure behaviour of the FFF-printed specimens subjected to different types of loading such as tensile, compressive and shear loading. Specimens are printed with a total of three print orientations (0, 0/90, and ± 45°) and three layer heights (50 μm, 125 μm, and 200 μm). X-ray computed tomography (CT) is employed to gain insights into the effects of printing process parameters on void formations, their size, shape and distribution in the FFF-printed specimens. During the loading event, full-field strain distribution and out-of-plane deflection of the specimens are obtained by utilizing the 3D digital image correlation (DIC) technique. The fractured specimens under tensile loading are further examined for the (3D) profiles of fractured surfaces and related fracture-causing mechanisms utilizing a high-resolution digital stereomicroscope. In addition, X-ray CT is also employed again to gain insights into the effects of loading type on the voids in deformed specimens. Voids and internal bead structures of both virgin and deformed specimens are compared to understand the deformation and failure mechanism of 3D printed specimens under various loading conditions. The shape, size, and distribution of the voids in the FDM printed specimens are observed to be highly dependent on the layer height and the print layout of the specimens. The content of voids is observed to be lowest in [0]_2N-printed specimens (3.54–7.69% for different layer heights), which increased approximately twice for [0/90]_N (7.69–13.61%) and approximately 2.5–3 times for [± 45]_N (10.44–14.66%). In addition, void content in the [0]_2N-printed specimens is observed to be the most sensitive to changes in layer height (approximately 117% variation between 50 and 200 µm), whereas least sensitive for [± 45]_N-printed specimens (approximately 40% variation between 50 and 200 µm). Furthermore, the mechanical response and failure behaviour of the specimens are also observed to be highly dependent on the considered printing process parameters owing to the changes in the void content and their effects on different print configurations and loading types.