Exploring multi-axis material extrusion additive manufacturing for improving mechanical properties of printed parts
ISSN: 1355-2546
Article publication date: 29 November 2018
Issue publication date: 25 February 2019
Abstract
Purpose
Material extrusion (ME) suffers from anisotropic mechanical properties that stem from the three degree of freedom (DoF) toolpaths used for deposition. The formation of each layer is restricted to the XY-plane, which produces poorly bonded layer interfaces along the build direction. Multi-axis ME affords the opportunity to change the layering and deposition directions locally throughout a part, which could improve a part’s overall mechanical performance. The purpose of this paper is to evaluate the effects of changing the layering and deposition directions on the tensile mechanical properties of parts printed via multi-axis ME.
Design/methodology/approach
A multi-axis toolpath generation algorithm is presented and implemented on a 6-DoF robotic arm ME system to fabricate tensile specimens at different global orientations. Specifically, acrylonitrile butadiene styrene (ABS) tensile specimens are printed at various inclination angles using the multi-axis technique; the resulting tensile strengths of the multi-axis specimens are compared to similarly oriented specimens printed using a traditional 3-DoF method.
Findings
The multi-axis specimens had similar performances regardless of orientation and were equivalent to the 3-DoF specimens printed in the XYZ orientation (i.e. flat on the bed with roads aligned to the loading condition). This similarity is attributed to those sets of specimens having the same degree of road alignment.
Practical implications
Parts with out-of-plane loads currently require design compromises (e.g. additional material in critical areas). Multi-axis deposition strategies could enable local changes in layering and deposition directions to more optimally orient roads in critical areas of the part.
Originality/value
Though multi-axis ME systems have been demonstrated in literature, no prior work has been done to determine the effects of the deposition angle on the resulting mechanical properties. This work demonstrates that identical mechanical properties can be obtained irrespective of the build direction through multi-axis deposition. For ABS, the yield tensile strength of vertically oriented tensile bars was improved by 153 per cent using multi-axis deposition as compared to geometrically similar samples fabricated via 3-DoF deposition.
Keywords
Acknowledgements
The authors would like to thank the Institute for Creativity, Arts and Technology at Virginia Tech for their financial support of this work.
Citation
Kubalak, J.R., Wicks, A.L. and Williams, C.B. (2019), "Exploring multi-axis material extrusion additive manufacturing for improving mechanical properties of printed parts", Rapid Prototyping Journal, Vol. 25 No. 2, pp. 356-362. https://doi.org/10.1108/RPJ-02-2018-0035
Publisher
:Emerald Publishing Limited
Copyright © 2018, Emerald Publishing Limited