scholarly journals Ionic Liquid Additives in Water-Based Lubricants for Bearing Steel – Effect of Electrical Conductivity and pH on Surface Chemistry, Friction and Wear

2022 ◽  
Vol 7 ◽  
Author(s):  
W. Wijanarko ◽  
H. Khanmohammadi ◽  
N. Espallargas

Water-based lubricants have the potential to become the largest environmentally friendly lubricants in applications such as electric vehicles and the newly emerging green technologies of the future due to their inherent low viscosity and cooling properties. In order to be environmentally acceptable (EAL), both base lubricants and additives should comply with biodegradability, non-toxicity, and non-bioaccumulation requirements. Additives for water-based lubricants should ideally be polar and soluble in water and, at the same time, should not increase the electrical conductivity to critical levels for corrosion. However, most additives used in synthetic or mineral oils are non-polar. Ionic liquids have recently gained attention as lubricant additives due to their high polarity, making them highly surface-active (i.e. high tendency to adsorb on metal surfaces). However, they are seen as highly corrosive for many metal alloys. In this work, a water-glycol lubricant containing two different ionic liquids has been investigated as a potential green lubricant for a bearing steel AISI 52100 with accurate control on electrical conductivity and pH. The selected ionic liquids were tributylmethylphosphonium dimethylphosphate (PP) and 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate (BMP). The tribological behaviour of the ionic liquids was compared with a well-known organic friction modifier, dodecanoic acid (C12). The ionic liquids showed lower friction and wear rate than the water-based lubricant alone. However, they showed higher friction than the lubricant formulated with C12, in which PP gave lower friction than BMP due to low pH. A detailed subsurface analysis of the wear track using scanning-transmission electron microscopy (STEM) showed that a thick oxide tribofilm was built on the wear track for both lubricants formulated with ionic liquids due to high electrical conductivity. This tribofilm gave beneficial effect on wear. Although PP and BMP gave thicker tribofilms than C12, it was not durable, resulting in cracking and detachment.

2013 ◽  
Vol 668 ◽  
pp. 547-550
Author(s):  
Ding Jun Zhang ◽  
Chao Yun Qu

Four ionic liquids containing dithiocarbazate were synthesized. Their antiwear and friction-reducing properties of these synthetic liquid compounds as the lubricants of a steel/steel contact were examined using an Optimol SRV oscillating friction and wear tester in ambient condition. The results indicated that the ionic liquids containing dithiocarbazate as the lubricants showed excellent friction-reducing and antiwear properties for the steel/steel pair. The introduction of the dithiocarbazate group into the molecules of the ionic liquids contributed to improve the tribological behaviour.


2016 ◽  
Vol 674 ◽  
pp. 250-256 ◽  
Author(s):  
Tobias Amann ◽  
Christian Dold ◽  
Andreas Kailer

Increase of energy efficiency, reliability and durability of technical systems in combination with resource conservation using environmentally friendly water-based lubricants would be an overarching goal in all tribological applications. According to this aim the objective of this work is to investigate and identify new water-based lubricants containing ionic liquids (ILs) to reduce friction and wear. Therefore the tribological behavior of different water-based ionic liquid mixtures, compared with a standard water based cooling lubricant emulsion, was studied using a ball-on-disk test. A three electrode setup was used to analyze the influence of different electric potentials. The results show that friction and wear can be improved by using ionic liquid. In addition, the tribological behavior can be strongly influenced by electric potentials. As tribological mechanism the attraction of cations and the formation of a triboactive layer is assumed, due to charging of the surface.


Lubricants ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 73
Author(s):  
Md Hafizur Rahman ◽  
Haley Warneke ◽  
Haley Webbert ◽  
Joaquin Rodriguez ◽  
Ethan Austin ◽  
...  

Water-based lubricants (WBLs) have been at the forefront of recent research, due to the abundant availability of water at a low cost. However, in metallic tribo-systems, WBLs often exhibit poor performance compared to petroleum-based lubricants. Research and development indicate that nano-additives improve the lubrication performance of water. Some of these additives could be categorized as solid nanoparticles, ionic liquids, and bio-based oils. These additives improve the tribological properties and help to reduce friction, wear, and corrosion. This review explored different water-based lubricant additives and summarized their properties and performances. Viscosity, density, wettability, and solubility are discussed to determine the viability of using water-based nano-lubricants compared to petroleum-based lubricants for reducing friction and wear in machining. Water-based liquid lubricants also have environmental benefits over petroleum-based lubricants. Further research is needed to understand and optimize water-based lubrication for tribological systems completely.


Friction ◽  
2021 ◽  
Author(s):  
Wahyu Wijanarko ◽  
Hamid Khanmohammadi ◽  
Nuria Espallargas

AbstractIonic liquids have been widely discussed as potential lubricants, however, their properties make them also very good potential candidates as lubricant additives (e.g., friction modifiers and anti-wear). In this work, the tribological study of two ionic liquids (tributylmethylphosphonium dimethylphosphate (PP), and 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate (BMP)) as lubricant additives has been performed on stainless steel (AISI 316L) exposed to polar (water-glycol) and non-polar (polyalphaolefin) based lubricants under boundary lubricating conditions. The performance of these ionic liquids as lubricant additives has been compared to a classical organic friction modifier (dodecanoic acid (C12)). The water-glycol lubricant formulated with the two ionic liquids showed friction values higher than the same base lubricant formulated with dodecanoic acid, however, opposite results were observed for polyalphaolefin (PAO). A detailed surface chemical analysis using X-ray photoelectron spectroscopy (XPS) revealed differences in the passive/tribofilm thickness and chemical composition of the stainless steel surface tested in all lubricants. In the case of the polar lubricant additivated with ionic liquids, the tribochemical reaction accompanied by a tribocorrosion process led to the formation of an unstable passive/tribofilm resulting in high friction and wear. However, in the absence of tribocorrosion process (polyalphaolefin base lubricant), the tribochemical reaction led to the formation of a stable passive/tribofilm resulting in low friction and wear. A detailed surface and subsurface investigation of the microstructure using scanning electron microscopy equipped with a focused ion beam (SEM-FIB) showed that high wear rates resulted in thicker recrystallization region under the wear track surface. Among all lubricant additives tested in this work, BMP in non-polar lubricant media showed the best tribological performance.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 732
Author(s):  
Yeoh Jun Jie Jason ◽  
Heoy Geok How ◽  
Yew Heng Teoh ◽  
Farooq Sher ◽  
Hun Guan Chuah ◽  
...  

This study investigated the tribological behaviour of Pongamia oil (PO) and 15W–40 mineral engine oil (MO) with and without the addition of graphene nanoplatelets (GNPs). The friction and wear characteristics were evaluated in four-ball anti-wear tests according to the ASTM D4172 standard. The morphology of worn surfaces and the lubrication mechanism of GNPs were investigated via SEM and EDS. This study also focuses on the tribological effect of GNP concentration at various concentrations. The addition of 0.05 wt % GNPs in PO and MO exhibits the lowest friction and wear with 17.5% and 12.24% friction reduction, respectively, and 11.96% and 5.14% wear reduction, respectively. Through SEM and EDS surface analysis, the surface enhancement on the worn surface by the polishing effect of GNPs was confirmed. The deposition of GNPs on the friction surface and the formation of a protective film prevent the interacting surfaces from rubbing, resulting in friction and wear reduction.


2020 ◽  
Vol 509 ◽  
pp. 112462
Author(s):  
Yuqiu Chen ◽  
Yingjun Cai ◽  
Kaj Thomsen ◽  
Georgios M. Kontogeorgis ◽  
John M. Woodley

Author(s):  
Tehreem Naveed ◽  
Rehan Zahid ◽  
Riaz Ahmad Mufti ◽  
Muhammad Waqas ◽  
Muhammad Talha Hanif

All the moving components in an internal combustion engine require a lubricant that allows smooth sliding and/or rolling of interacting surfaces. Lubricant not only minimizes the friction and wear but also dissipates the heat generated due to friction and removes debris from the area of contact. Environmental concerns, decreasing mineral oil reserves and difficult disposal of nonbiodegradable conventional lubricants have urged the researchers to shift towards environmental-friendly lubricants. Number of tribological studies carried out in the past have proved that ionic liquid-based bio-lubricants are sustainable and biodegradable alternative to mineral oils. This paper presents a brief review of properties of ionic liquids and their ability to reduce friction and wear between the interacting surfaces. Tribological performance and compatibility of ionic liquids with various base-oils have been compared under boundary lubrication. The results reveal that phosphonium-based ionic liquids namely tetra-decyl tri-hexyl phosphonium bis(2,4,4-trimethylpentyl) phosphinate (P66614)i(C8)2PO2 and tri-hexyl tetra-decyl phosphonium bis(2-ethylhexyl) phosphate (P-DEHP) are more suitable for tribological applications. Since, ionic liquids can be tailored according to the application and millions of combinations are possible therefore, there is a need to summarize the published data in a more systematic and logical way.


2018 ◽  
Vol 33 (6) ◽  
pp. 828-850 ◽  
Author(s):  
R Vinayagamoorthy

The dominance of fibre-reinforced plastics in industries has enhanced the need for research to develop new composites and assess their properties. Among the various property analyses, tribological characteristics of the composites help to understand the friction and wear behaviour. This article presents a comprehensive survey on the tribological behaviour of polymeric composites, which includes the influence of various working parameters such as the velocity of sliding, sliding distance, pressure applied and temperature on the friction and wear. The article also addresses about the importance of the composite constituents such as fibre composition, fibre geometry and fibre orientation on the tribological behaviour. The major reasons causing the tribological failure like the debonding between the fibre and the matrix, failure of the matrix and the fibre are also extensively addressed. This review would be an insight to the industries and tribology researchers towards achieving optimum design for the components made of polymers.


Sign in / Sign up

Export Citation Format

Share Document