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Dhakal, N., Espejo, C., Morina, A. & Emami, N. (2024). Tribological performance of 3D printed neat and carbon fiber reinforced PEEK composites. Tribology International, 193, Article ID 109356.
Open this publication in new window or tab >>Tribological performance of 3D printed neat and carbon fiber reinforced PEEK composites
2024 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 193, article id 109356Article in journal (Refereed) Published
Abstract [en]

This work investigates the tribological behavior of neat and carbon fiber-reinforced polyether-ether-ketone (PEEK) materials processed using the fused filament fabrication (FFF) technique. The reciprocating sliding behavior of printed polymers against stainless steel (SS) under dry and water-lubricated conditions was studied. The running-in behavior and evolution of friction were dependent on the material combination and sliding conditions. PEEK reinforced with 10 wt% carbon fibers was optimal considering tribological performance. Neat PEEK exhibited a combination of abrasive and adhesive wear mechanisms, while composites primarily showed fiber-matrix debonding and delamination during sliding. The outcome of this work has significance in improving the processing design of PEEK-based materials in extrusion-based 3D printing for tribological applications.

Keywords
3D printing, Tribology, Polymer composites, PEEK, Friction and wear, Dry sliding, Water lubrication
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-104347 (URN)10.1016/j.triboint.2024.109356 (DOI)2-s2.0-85183995970 (Scopus ID)
Funder
EU, Horizon 2020, 860246
Note

Validerad;2024;Nivå 2;2024-02-21 (signyg);

Full text license: CC BY

Available from: 2024-02-21 Created: 2024-02-21 Last updated: 2024-04-19Bibliographically approved
Dhakal, N., Wang, X., Espejo, C., Morina, A. & Emami, N. (2023). Impact of processing defects on microstructure, surface quality, and tribological performance in 3D printed polymers. Journal of Materials Research and Technology, 23, 1252-1272
Open this publication in new window or tab >>Impact of processing defects on microstructure, surface quality, and tribological performance in 3D printed polymers
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2023 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 23, p. 1252-1272Article in journal (Refereed) Published
Abstract [en]

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 × 10−5 mm3/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.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
3D printing, Tribology, Friction, Polymers, Porosity, Surface roughness
National Category
Manufacturing, Surface and Joining Technology Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-95552 (URN)10.1016/j.jmrt.2023.01.086 (DOI)000964378800001 ()2-s2.0-85149695807 (Scopus ID)
Funder
EU, Horizon 2020, 860246
Note

Validerad;2023;Nivå 2;2023-03-21 (joosat);

Licens fulltext: CC BY License

Available from: 2023-02-08 Created: 2023-02-08 Last updated: 2024-03-07Bibliographically approved
Dhakal, N., Shi, Y. & Emami, N. (2022). Tribological behaviour of UHMWPE composites lubricated by polyvinylpyrrolidone‐modified water. Lubrication Science, 34(1), 42-53
Open this publication in new window or tab >>Tribological behaviour of UHMWPE composites lubricated by polyvinylpyrrolidone‐modified water
2022 (English)In: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 34, no 1, p. 42-53Article in journal (Refereed) Published
Abstract [en]

Tribological characteristics of ultra-high molecular weight polyethylene (UHMWPE) composites with 10% short carbon fibres (SCF) lubricated in water with polyvinylpyrrolidone (PVP) as a modifier were investigated. The aqueous solutions with varying concentrations of PVP were prepared, and their viscosity-enhancing action, friction-reducing properties and anti-wear performances were studied under different loading conditions equivalent to 10 and 20 MPa of contact pressures at a constant sliding speed of 20 mm/s. The results showed that PVP is an excellent viscosity modifier for water. PVP-modified water exhibited excellent performance compared to distilled water, reducing the wear and friction coefficient of neat UHMWPE up to 25%. The anti-wear properties of UHMWPE-SCF composite were also improved with PVP modified water lubrication, yielding a maximum reduction of wear up to 45%. PVP seems to be a promising additive of modifying the lubricating properties of distilled water for water-based lubrication. 

Place, publisher, year, edition, pages
John Wiley & Sons, 2022
Keywords
composites, lubrication, polyvinylpyrrolidone (PVP), UHMWPE, water
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-87379 (URN)10.1002/ls.1570 (DOI)000701227900001 ()2-s2.0-85116064073 (Scopus ID)
Note

Validerad;2022;Nivå 2;2022-03-01 (joosat)

Available from: 2021-10-05 Created: 2021-10-05 Last updated: 2023-09-06Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9346-7229

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