Elasto-hydrodynamic friction changes on steel surfaces arising from the modified surface energy of the steel due to additive boundary films

Marko Polajnar (Author), Benoît Thiébaut (Author), Frederic Jarnias (Author), Mitjan Kalin (Author)

Abstract

The effect of three different film-forming additives mixed in PAO oil on the elasto-hydrodynamic (EHD) friction was investigated and compared to cases with the base oil only. When the boundary films were formed on the surfaces, the organic friction modifier (OFM) decreased the EHL friction by up to 8.7%, the ionic liquid (IL) decreased it by up to 6.4%, while the polymeric organic friction modifier (pOFM) increased it by up to 4.2%. In contrast, if the boundary films were not formed, the EHL friction remained the same as with the base oils only. The oils` surface tension and viscosity were analysed at 25 °C and 100 °C as potential influencing effects, and the most important parameter for friction changes was found to be the surface energy. The mechanism behind this EHL friction reduction is, therefore, the effect of the boundary films on the poor oil-surface wetting and the consequent boundary slip. This study confirms the poor wetting arising from additive boundary-film formation as a relevant EHL friction-reduction mechanism. This observation is similar to that observed previously for surface coatings, thus suggesting that the boundary films of the surface-energy-reducing additives is a parameter with the potential to reduce the EHL friction.

Keywords

elastohydrodynamic;lubricant additive;traction;wetting;

Data

Language:	English
Year of publishing:	2021
Typology:	1.01 - Original Scientific Article
Organization:	UL FS - Faculty of Mechanical Engineering
UDC:	531.43:669.14:544.722.3
COBISS:	73795843
ISSN:	0301-679X
Views:	249
Downloads:	20
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	elastohidrodinamika;aditivi za maziva;trenje;omočljivost;
Type (COBISS):	Article
Embargo end date (OpenAIRE):	2023-07-24
Pages:	str. 1-10
Issue:	ǂVol. ǂ164
Chronology:	Dec. 2021
DOI:	10.1016/j.triboint.2021.107203
ID:	13275163