Nayan Dhakal (1) (2), Xiaolong Wang (3), Cayetano Espejo (2), Ardian Morina (2), Nazanin Emami (1)
Journal of Materials Research and Technology. Volume 23, Pages 1252-1272 (21 January 2023). DOI: https://doi.org/10.1016/j.jmrt.2023.01.086

Keywords

3D printing, tribology, friction, polymers, porosity, surface roughness

Abstract

Additive manufacturing (AM), also known as three-dimensional (3D) printing, of polymer-based materials is growing as a time-efficient, economical, and environmentally sustainable technique for prototype development in load-bearing applications. This work investigates the defects arising from the processing in material extrusion-based AM of polymers and their impact on the part performance. The influence of raster angle orientation and printing speed on tribological characteristics, microstructure, and surface finish of acrylonitrile butadiene styrene (ABS) fabricated in a heated build chamber was studied. Comprehensive analysis with fractography and tomography revealed the formation, distribution, and locations of internal voids, while surface defects were studied with the topography analysis of as-printed surfaces. Surface roughness and tribological results show that printing speed can be optimally increased with a minimal impact on interlayer bonding and part performance. Increased printing speed allowed up to 58% effective reduction in printing time obtaining comparable mechanical properties at varying process parameters. 3D printed ABS exhibited dry sliding friction coefficients in the range of 0.18–0.23, whilst the maximum specific wear rate was 6.2 × 10−5mm3/Nm. Higher surface roughness and increased printing speed exhibited delayed running-in during dry sliding, while insignificant influence was observed for steady-state friction and wear behaviors. The findings indicate that improved surface finish and reduced internal defects can be achieved with a controlled build environment allowing for higher printing speed. The observations in this study are evidence that 3D printing can be adapted for the sustainable manufacturing of polymeric components for tribological applications.

How Our Software Was Used

Visualizations and porosity analysis from XMT scanned data were done with Dragonfly Pro. The pore segmentation was performed in a multiple-step workflow that included image filtering, thresholding, and morphological operations. Finally, a new multi-ROI was created with all identified pores as separate entities for the calculations of volume fractions and porosity distribution.

Author Affiliation

(1) Polymer-tribology Group, Division of Machine Elements, Luleå University of Technology, SE 97187, Luleå, Sweden
(2) Institute of Functional Surfaces, School of Mechanical Engineering, University of Leeds, LS2 9JT, Leeds, United Kingdom
(3) State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, CAS, Lanzhou, 730000, China