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Publications (10 of 19) Show all publications
Wu, J., Huang, X., Berglund, K., Lu, X., Feng, X., Larsson, R. & Shi, Y. (2018). CuO nanosheets produced in graphene oxide solution: An excellent anti-wear additive for self-lubricating polymer composites. Composites Science And Technology, 162, 86-92
Open this publication in new window or tab >>CuO nanosheets produced in graphene oxide solution: An excellent anti-wear additive for self-lubricating polymer composites
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2018 (English)In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 162, p. 86-92Article in journal (Refereed) Published
Abstract [en]

In the present work, graphene oxide is used as template to produce CuO nanosheets, which solves aggregation and dispersion problems of CuO nanosheets resulting in improved lubricating performance. SEM and AFM studies show that CuO nanosheets are present in fusiform flake shape with a thickness, width and length of around 13, 400 and 1000 nm, respectively. CuO nanosheets were added to the carbon fibers reinforced Polytetrafluoroethylene (CF/PTFE) to study their lubricating performance. It is interesting, from fractured surfaces of composites, to find that CuO nanosheets enhance the interface properties between carbon fibers and PTFE. The wear resistance property of CF/PTFE is remarkably improved after filling CuO nanosheets. For example, the wear rate is reduced by 51% after filling 1.5 wt % CuO nanosheets. The wear resistance improvement effect of CuO nanosheets is much better than that of commercial CuO nanogranules and CuO nanorods. Worn surfaces and counter-surfaces studying indicates that CuO nanosheets can not only prevent the rubbed-off of PTFE or the detachment of CF, but also improve the properties of transfer films, which greatly reduce the adhesive wear and abrasive wear.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-68387 (URN)10.1016/j.compscitech.2018.04.020 (DOI)000438180500010 ()2-s2.0-85046114065 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-05-09 (andbra)

Available from: 2018-04-17 Created: 2018-04-17 Last updated: 2018-08-09Bibliographically approved
Berglund, K. & Shi, Y. (2017). Friction and Wear of Self-Lubricating Materials for Hydropower Applications under Different Lubricating Conditions. Lubricants, 5(3), Article ID 24.
Open this publication in new window or tab >>Friction and Wear of Self-Lubricating Materials for Hydropower Applications under Different Lubricating Conditions
2017 (English)In: Lubricants, ISSN 2075-4442, Vol. 5, no 3, article id 24Article in journal (Refereed) Published
Abstract [en]

Self-lubricating bearings in hydropower applications are often lubricated with water under boundary lubricating conditions. Polyhydric alcohols replacing water have shown the potential to reduce both friction and wear. The objective of this work is, therefore, to evaluate the effect of a polyhydric alcohol-based environmentally-acceptable lubricant (EAL) on the friction and wear of self-lubricating materials for conformal contacts under boundary lubricating conditions. The lubricating properties of four commercially-available self-lubricating bearing materials were investigated under three different lubricating conditions: dry, water and a new polyhydric alcohol-based EAL. Bearing materials include one metallic composite and three polymer composites. A reciprocating motion test rig was used to evaluate the wear and friction properties. Surface analysis was performed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and optical profilometry. Results show that the wear rate for the polymer composites is increased when water is present compared to dry operating conditions. The new polyhydric alcohol-based EAL substantially improves both friction and anti-wear performance of all four self-lubricating bearing materials compared to both dry and water conditions. Surface analysis indicates that the material transfer to the counter-surface is limited when the polyhydric alcohol-based EAL is used.

Place, publisher, year, edition, pages
MDPI, 2017
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-65141 (URN)10.3390/lubricants5030024 (DOI)000410639100005 ()2-s2.0-85029493385 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-08-16 (andbra)

Available from: 2017-08-16 Created: 2017-08-16 Last updated: 2018-07-10Bibliographically approved
Björling, M., Berglund, K., Spencer, A. & Larsson, R. (2017). The effect of ageing on elastohydrodynamic friction in heavy-duty diesel engine oils. Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 231(6), 708-715
Open this publication in new window or tab >>The effect of ageing on elastohydrodynamic friction in heavy-duty diesel engine oils
2017 (English)In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 231, no 6, p. 708-715Article in journal (Refereed) Published
Abstract [en]

To further improve the efficiency of machine components found in automotive engine systems it is important to understand the friction generation in these components. Modelling and simulation of these components are crucial parts of the development process. Accurate simulation of the friction generated in these machine components is, amongst other things, dependent on realistic lubricant rheology and lubricant properties, where especially the latter may change during ageing of the lubricant. Many modern heavy-duty diesel engines are in operation for several hundred hours before the engine oil is changed. In this work, two engine oils, one 10 W-30 and one 5 W-20, have been aged in full heavy-duty diesel engine bench tests for 400 and 470 hours respectively. This roughly corresponds to the amount of ageing these oils are subjected to between oil drains in field conditions. The aged oils were subjected to a number of oil analyses showing, among other things, a maximum increase in oil viscosity of 12.9% for the 5 W-20 oil and 5.5% for the 10 W-30 oil, which is most likely primarily an effect of evaporation and oxidation. The aged oils were tested in a ball-on-disc test rig under elastohydrodynamic conditions where friction was measured and the performance was compared to fresh samples of the same oils. The results show that there is almost no difference in elastohydrodynamic friction when comparing the aged oils with the fresh oils. These results indicate that it is not necessary to include oil ageing in numerical elastohydrodynamic friction models as long as the oil is changed before the ageing has reached a critical level

Place, publisher, year, edition, pages
Sage Publications, 2017
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-63610 (URN)10.1177/1350650116674848 (DOI)000402067300004 ()2-s2.0-85019744905 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-05-30 (andbra)

Available from: 2017-05-30 Created: 2017-05-30 Last updated: 2018-07-10Bibliographically approved
Emadi, M., Berglund, K. & Minami, I. (2016). Does your lubrication system conform to the concept of green chemistry? (ed.). In: (Ed.), : . Paper presented at 20th International Colloquium Tribology : 12/01/2016 - 14/01/2016.
Open this publication in new window or tab >>Does your lubrication system conform to the concept of green chemistry?
2016 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

We frequently find “EAL” (environmentally acceptable lubricant or relevant such as “environmentally friendly,” “environmentally adapted,” “environmental benign,” “biodegradable,” “ecological,” “green,” in the title and keywords of tribology papers. It intimates "something good for environment" and may catch the readers' attention. However, one might feel unease because the definition of these terms is unclear. These terms are too loosely used with the authors’ satisfaction in most cases. Of course, lubrication engineering contributes to protect global environment by improving energy efficiency and prolonging machine life through reducing friction and wear. In this regard, lubrication itself is definitely one of the “green” technologies. This led a simple question – why adjectives such as “environmental” are used with lubrication? The unrivalled reference book in tribology defines “environmentally friendly lubricants” as “readily biodegradable in nature” [1]. We agree with it, but shall ask "is biodegradability enough for protection of global environment?" This motivated us to propose unambiguous criteria for EAL.

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-37718 (URN)bd3f9de3-5403-4279-9f1d-3767acf90726 (Local ID)bd3f9de3-5403-4279-9f1d-3767acf90726 (Archive number)bd3f9de3-5403-4279-9f1d-3767acf90726 (OAI)
Conference
20th International Colloquium Tribology : 12/01/2016 - 14/01/2016
Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-01-14Bibliographically approved
Berglund, K., Emadi, S. & Minami, I. (2016). Lubricant Maintenance Based on Condition Monitoring. In: STLE 2016 Annual Meeting and Exhibition: . Paper presented at 71st STLE Annual Meeting and Exhibition will be held in Las Vegas, Nevada, May 15-19, 2016.
Open this publication in new window or tab >>Lubricant Maintenance Based on Condition Monitoring
2016 (English)In: STLE 2016 Annual Meeting and Exhibition, 2016Conference paper, Oral presentation with published abstract (Refereed)
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-41893 (URN)
Conference
71st STLE Annual Meeting and Exhibition will be held in Las Vegas, Nevada, May 15-19, 2016
Available from: 2016-10-04 Created: 2016-10-04 Last updated: 2018-01-14Bibliographically approved
Berglund, K. & Shi, Y. (2016). Performance of self‐lubricating materials for hydropower applications under different lubricating conditions. In: Nordic Symposium on Tribology - NORDTRIB 2016: . Paper presented at 17th Nordic Symposium on Tribology - NORDTRIB 2016, Aulanko, Hämeenlinna, Finland, 14–17 June 2016.
Open this publication in new window or tab >>Performance of self‐lubricating materials for hydropower applications under different lubricating conditions
2016 (English)In: Nordic Symposium on Tribology - NORDTRIB 2016, 2016Conference paper, Published paper (Refereed)
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-41891 (URN)
Conference
17th Nordic Symposium on Tribology - NORDTRIB 2016, Aulanko, Hämeenlinna, Finland, 14–17 June 2016
Available from: 2016-10-04 Created: 2016-10-04 Last updated: 2018-02-05
Berglund, K., Marklund, P., Lundh, H. & Larsson, R. (2016). Prediction of driveline vibrations caused by ageing the limited slip coupling (ed.). Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, 230(12), 1687-1698
Open this publication in new window or tab >>Prediction of driveline vibrations caused by ageing the limited slip coupling
2016 (English)In: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, ISSN 0954-4070, E-ISSN 2041-2991, Vol. 230, no 12, p. 1687-1698Article in journal (Refereed) Published
Abstract [en]

The prediction of the wet-clutch service life still remains a challenge for scientists and engineers. Previous research has shown the significance of the wet-clutch friction characteristics on the driveline dynamics. To avoid driveline vibrations an increasing friction coefficient with increasing sliding speed is desirable. Consequently, prediction of the occurrence of driveline vibrations relies on a detailed knowledge of how the friction characteristics are affected by wet-clutch degradation, as well as an understanding of the driveline dynamics. Wet clutches are used in both automatic transmissions and all-wheel-drive systems in cars, where they are referred to as limited slip couplings by manufacturers. Wet clutches used in automatic transmissions are subjected to high slip levels, but for very limited time periods. In all-wheel-drive systems, where the limited slip coupling can be used to control the torque transfer to, for example, the rear wheels, the slip levels are low but continuous. Most wet-clutch research has been performed for clutches in automatic transmissions and not for clutches used in all-wheel-drive systems. Thus, a simulation model was developed to evaluate how different operating conditions of the limited slip coupling influence degradation of the friction characteristics and the tendencies towards driveline vibrations. First, the changes in the friction characteristics with the time of ageing are simulated. The friction characteristics after ageing are used as the input to a simplified driveline model, which is used to evaluate the occurrence of vibrations. It is shown how the developed simulation model can be used as an efficient tool for engineers. The developed simulation model can be used to predict how the operating conditions for the limited slip coupling influence degradation of the friction characteristics.

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-4024 (URN)10.1177/0954407015619505 (DOI)000383949700006 ()2-s2.0-84988328397 (Scopus ID)1e0ebf18-27ea-4e0e-8161-974736d58461 (Local ID)1e0ebf18-27ea-4e0e-8161-974736d58461 (Archive number)1e0ebf18-27ea-4e0e-8161-974736d58461 (OAI)
Note

Validerad; 2016; Nivå 2; 2016-10-14 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Shi, Y., Vadivel, H. & Berglund, K. (2016). Studying the tribological properties of PEEK composites lubricated by different lubricants for hydropower turbine application. In: Nordic Symposium on Tribology - NORDTRIB 2016: . Paper presented at 17th Nordic Symposium on Tribology - NORDTRIB 2016, Aulanko, Hämeenlinna, Finland, 14–17 June 2016.
Open this publication in new window or tab >>Studying the tribological properties of PEEK composites lubricated by different lubricants for hydropower turbine application
2016 (English)In: Nordic Symposium on Tribology - NORDTRIB 2016, 2016Conference paper, Published paper (Refereed)
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-41892 (URN)
Conference
17th Nordic Symposium on Tribology - NORDTRIB 2016, Aulanko, Hämeenlinna, Finland, 14–17 June 2016
Available from: 2016-10-04 Created: 2016-10-04 Last updated: 2018-02-05
Fatima, N., Minami, I., Holmgren, A., Marklund, P., Berglund, K. & Larsson, R. (2015). Influence of water on the tribological properties of zinc dialkyl-dithiophosphate and over-based calcium sulfonate additives in wet clutch contacts (ed.). Paper presented at . Tribology International, 87, 113-120
Open this publication in new window or tab >>Influence of water on the tribological properties of zinc dialkyl-dithiophosphate and over-based calcium sulfonate additives in wet clutch contacts
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2015 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 87, p. 113-120Article in journal (Refereed) Published
Abstract [en]

Usually the wet clutch lubricant properties vary with different formulations of base oil types and additives. The aim of this paper was to evaluate the effect of water on the performance of additives in ATF. Simplified lubricants, ZDDP and over-based Ca-sulfonates detergent additives in an API Group I mineral base oil, were employed to compare with the commercial fully-formulated automatic transmission fluid (DEXRON®VI) during water-contamination. A full-scale wet clutch test rig was used to evaluate the frictional response due to water contamination of the lubricants. Fourier Transform Infrared Spectroscopy was utilized to evaluate the variation in the solubility of these polar organic additives in the water phase and Karl-Fischer titration was utilized to evaluate the post-test water content for different formulations.

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Chemical Process Engineering
Research subject
Machine Elements; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-13289 (URN)10.1016/j.triboint.2015.02.006 (DOI)000353730500013 ()2-s2.0-84924913600 (Scopus ID)c7d39d15-0ec2-4a97-b3fa-72d8755bdd6a (Local ID)c7d39d15-0ec2-4a97-b3fa-72d8755bdd6a (Archive number)c7d39d15-0ec2-4a97-b3fa-72d8755bdd6a (OAI)
Note
Validerad; 2015; Nivå 2; 20150213 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Berglund, K., Marklund, P., Larsson, R. & Olsson, R. (2014). Evaluating lifetime performance of limited slip differentials (ed.). Paper presented at . Lubrication Science, 26(3), 189-201
Open this publication in new window or tab >>Evaluating lifetime performance of limited slip differentials
2014 (English)In: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 26, no 3, p. 189-201Article in journal (Refereed) Published
Abstract [en]

Extensive research has been performed regarding wet clutch function and performance. Although wet clutches are used in both automatic transmissions and limited slip differentials in cars, most research has been performed for wet clutches incorporated in automatic transmissions. The operating conditions of wet clutches in automatic transmissions differ from the operating conditions of the wet clutches used in limited slip differentials. Therefore, a method and a test bench to use in the investigation of the degradation of limited slip differentials were developed in this work. The typical operating conditions of the limited slip differential and the differences compared with wet clutches incorporated in automatic transmissions were also addressed. Tests performed showed that the developed test bench and method can be used to address differences in frictional response over time for different types of operating condition

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-3235 (URN)10.1002/ls.1244 (DOI)000332986100004 ()2-s2.0-84895927138 (Scopus ID)1094301b-2921-4c5d-a254-79decdb81712 (Local ID)1094301b-2921-4c5d-a254-79decdb81712 (Archive number)1094301b-2921-4c5d-a254-79decdb81712 (OAI)
Note
Validerad; 2014; 20131218 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8533-897x

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