Polyaniline as an additive towards improving tribological properties and anti-corrosion performance of ionic liquids-based greases

2020 ◽  
Vol 72 (7) ◽  
pp. 851-856
Author(s):  
Zhengfeng Cao ◽  
Yanqiu Xia ◽  
Chuan Chen ◽  
Kai Zheng ◽  
Yi Zhang

Purpose This paper aims to explore polyaniline (PANI) as a lubricant additive to improve the anti-corrosion and tribological properties of ionic liquids (ILs) for actual applications. Design/methodology/approach ILs were synthesized by dissolving lithium salts in synthetic oil and were used as a base oil to prepare ILs-based greases. PANI was used as an additive. The tribological properties were investigated in detail and the anti-corrosion ability was also assessed via salt spray test. After friction test, the worn surfaces were characterized by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy to analyze the lubrication mechanisms. Findings PANI not only reduces the corrosion but also improves the friction reduction and anti-wear abilities of the ILs-based greases. The analysis indicates that the protective films generated on the worn surfaces were responsible for the preferable anti-corrosion and tribological properties. Originality/value This paper provides an effective approach to improve the anti-corrosion and tribological properties of ILs for actual applications. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0469/

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yanqiu Xia ◽  
Chen Chen ◽  
Xin Feng ◽  
Zhengfeng Cao

Purpose The purpose of this paper is to synthesize a kind of core-shell Ag@polyaniline (Ag@PAN) as a lubricant additive to improve the friction reduction and anti-wear abilities of lithium-based complex grease. Design/methodology/approach The core-shell Ag@PAN was prepared by a simple method and was introduced into the lithium-based complex grease. The typical properties of Ag@PAN were investigated by scanning electron microscopy (SEM), Fourier transforms infrared spectrometer and thermal gravimetric analyzer. The tribological properties were evaluated under different conditions. After the tribological test, the worn surface was analyzed by SEM and X-ray photoelectron spectroscopy to probe the lubrication mechanisms. Findings The prepared Ag@PAN could greatly improve the friction reduction and wear resistance of the friction pair under different conditions. The preferable tribological performances were mainly attributed to the synergism of various lubrication mechanisms including “mending effect,” “rolling effect” and lubricating protective film, and so on. Originality/value This study synthesizes a new kind of core-shell Ag@PAN as a lubricant additive, and it possesses preferable friction reduction and anti-wear abilities.


Author(s):  
Lifeng Hao ◽  
Feng Cao ◽  
Zewen Jiang ◽  
Jiusheng Li ◽  
Tianhui Ren

Oil-soluble compounds containing boron as lubricating additives were restricted by the hydrolysis of borate ester. In order to overcome this problem, cerium borate nanoparticles modified with oleic acid (O-CeB) as a potential substitute for conventional lubricant additive were studied in detail. The microstructures of the prepared nanoparticles were characterized. Tribological properties of cerium borate nanoparticles used as additive in base oil were evaluated, and the worn surface of the steel ball was investigated. The results show that O-CeB possesses better anti-wear ability at relatively higher concentration; in particular, it shows better friction-reducing ability under all these studied concentrations. Under higher load, its anti-wear property and friction-reducing property are better than that of Vanlube 289 in the base oil. Based on these results of interferometric surface profilometer and X-ray photoelectron spectroscopy, it can be deduced that a continuous resistance film containing depositions and the tribochemical reaction products was formed during the sliding process.


2007 ◽  
Vol 129 (4) ◽  
pp. 913-919 ◽  
Author(s):  
Xun Fu ◽  
Xiaodong Zhou ◽  
Huaqiang Shi ◽  
Danmei Wu ◽  
Zhengshui Hu

The tribological properties of MoS2 microsized spheres (MS-MoS2) with diameter of 0.5–3μm modified by self-prepared surfactant quaternary ammonium salt of 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI) as an additive in base oil 500 SN were investigated and compared with those of commercial colloidal MoS2(CC-MoS2) on a four-ball tester and an Optimol SRV oscillating friction and wear tester in a ball-on-disk contact configuration. The worn surfaces of the bottom flat disk were examined with scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the MoS2 microsized spheres product was a much better extreme-pressure additive and antiwear and friction-reduction additive in 500 SN than commercial colloidal MoS2(CC-MoS2). Under the appropriate concentration of 0.1% and 0.25% for MS-MoS2 and CC-MoS2 and the load of 400N, the friction coefficient of MS-MoS2/oil and CC-MoS2/oil decreased about 25.0% and 12.5% and the wear volume loss decreased about 50.4% and 12.9% compared with the pure base stock. The boundary lubrication mechanism could be deduced as the effective chemical adsorption film formed by the long chain alkyl (C11H23) and active elements (S and N) in the surfactant SUDEI and tribochemical reaction film composed of the tribochemical reaction products.


2018 ◽  
Vol 70 (5) ◽  
pp. 878-887 ◽  
Author(s):  
Zeqi Jiang ◽  
Jianhua Fang ◽  
Fei Chen ◽  
Boshui Chen ◽  
Kecheng Gu

Purpose This paper aims at understanding tribological properties of lubricating oils doped with zinc dithiophosphate(ZDDP) with and without electromagnetic field impact. Design/methodology/approach The friction and wear properties of the oils formulated with zinc butyloctyl dithiophosphate (T202) or zinc dioctyl dithiophosphate (T203) under electromagnetic field or nonelectromagnetic field were evaluated on a modified four-ball tribotester. The characteristics of the worn surfaces obtained from electromagnetic or nonelectromagnetic field conditions were analyzed by scanning electronic microscopy, energy dispersive spectrometer and X-ray photoelectron spectroscopy. This paper focuses on understanding influence of electromagnetic field on lubrication effect of the ZDDP-formulated oils. Findings The electromagnetic field could effectively facilitate anti-wear and friction-reducing properties of the oils doped with T202 or T203 as compared to those without electromagnetism affection, and the T203-doped oils were more susceptible to the electromagnetic field. The improvement of anti-wear and friction-reducing abilities of the tested oils were mainly attributed to the promoted tribochemical reactions and the modification of the worn surfaces (forming Zn-Fe solid solution) induced by the electromagnetic field. Originality/value This paper has revealed that tribological performances of ZDDP-doped oils could be improved by the electromagnetic field and discussed its lubrication mechanisms. Investigating tribological properties of additives from the viewpoint of electromagnetics is a new attempt, which has significance not only for the choose and designing of additives in electromagnetic condition but also for development of tribological theories and practices.


2019 ◽  
Vol 72 (1) ◽  
pp. 54-65
Author(s):  
Ming Yang ◽  
Zhengfeng Jia ◽  
Denghu Wei ◽  
Yunxia Wang ◽  
Xianjuan Pang ◽  
...  

Purpose The purpose of this paper is to investigate the tribological properties of carbonized polydopamine/reduced graphene oxide (CPDA/rGO) composite coatings. Design/methodology/approach CPDA/rGO composite coatings were prepared using the spray technique and subsequent pyrolysis under argon. The transmission electron microscopy, field-emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy revealed the conversion of PDA and GO into CPDA and rGO, respectively. Findings The results of tribological investigations show that the CPDA/rGO composite coatings with heat treatment at 300°C possess much better friction-reduction and anti-wear properties. Originality/value The worn surfaces of the PDA/GO composite films after heat treatment at 300°C were much smoother than that of the copper substrate. The tribofilms containing C, N, O and Cu played an important role on reducing friction and increasing wear resistance.


2020 ◽  
Vol 72 (3) ◽  
pp. 307-314
Author(s):  
Yong Qian ◽  
Hongying Gong ◽  
Xiaoyun Zhao ◽  
Lei Cao ◽  
Weizhong Shi ◽  
...  

Purpose The purpose of this study is to corroborate the advanced tribological properties of graphene as a lubricant additive. Design/methodology/approach Different concentrations of functionalized graphene were coated on the substrate surface. Tribological properties of the graphene lubricants were carried out by ball-on-disk tribology tests. Wear mechanism of functionalized graphene was studied by observing wear scars on the substrate surface. Finally, the wear resistance of modified graphene was calculated by calculating and analyzing the applied experimental conditions and the obtained experimental data. Findings The best concentration of graphene lubricant is 0.5 wt.% which shows the best tribological performance. And the coefficient of friction is 0.08. Compared with the dry friction condition, the coefficient of friction and wear rate of best graphene lubricant decreased by 80% and 82%. Originality/value The formula of graphene lubricant is independently developed and works very well. Graphene lubricant can prevent the substrate from oxidation. The thickness of the graphene lubricant is about 4-7µm. The concept of anti-wear strength was introduced in this paper. When 0.5 Vol.% graphene was added, the anti-wear strength was greatly improved from 115.3 kg·mm-2 to 657.6 kg·mm-2. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0344


2019 ◽  
Vol 71 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Chang Dong ◽  
Jianlin Sun ◽  
Zixuan Cheng ◽  
Yuqing Hou

Purpose The purpose of this paper is to synthesize a microemulsion and investigate its tribological properties as lubricant. Magnesium alloy warm rolling experiments were conducted. Surface morphology was observed and wear form was summarized. The composition of surface residues was analyzed, which sheds light on the lubrication mechanism of microemulsion. Design/methodology/approach A microemulsion was prepared with a proper amount of oil, surfactant, cosurfactant, water and other additives for magnesium alloy strip warm rolling. Tribological properties, such as maximum non-seizure load (PB), friction coefficient (μ) and wear scar diameter (D) of the microemulsion were measured and compared with those of emulsion and rolling oil on an MR-10A four-ball tribotester. The extreme pressure anti-wear coefficients (O) were calculated and compared. Warm rolling experiments were carried out on a Ф 170/400 × 300 mm four-high rolling mill at 240°C to compare the finish rolling thickness and surface quality of rolled AZ31B magnesium alloy strip under four lubrication states, namely, no lubrication, rolling oil, microemulsion and emulsion. The surface morphology after warm rolling was observed with confocal laser scanning microscope and scanning electron microscope, respectively. The composition of surface residues was analyzed with energy dispersive spectrometry and X-Ray photoelectron spectroscopy. Findings Surface morphology indicated that pitting wear, adhesive wear and ploughing wear were three main forms of wear in magnesium alloy warm rolling. Microemulsion had excellent lubrication properties with less residual oil remaining. Two types of adsorption layers formed on magnesium alloy strip surface were responsible for lubrication properties. MgSO4 and magnesium stearate in the reaction layer played a key role in anti-wear and friction-reduction in warm rolling. Originality/value The study is original and gives valuable information on lubrication mechanism of microemulsion in warm rolling of magnesium alloy strips.


2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Wang Li-jun ◽  
Guo Chu-wen ◽  
Ryuichiro Yamane

The synthesis and application of nanometer-sized particles have received considerable attention in recent years because of their different physical and chemical properties from those of the bulk materials or individual molecules; however, few experimental investigations on the tribological properties of lubricating oils with and without nanoferromagnetic particles have been performed. This work investigates the tribological properties of Mn0.78Zn0.22Fe2O4 nanoferromagnetic as additive in 46# turbine oil using a four-ball friction and wear tester. It is shown that the 46# turbine oil containing Mn0.78Zn0.22Fe2O4 nanoparticles has much better friction reduction and antiwear abilities than the base oil. The 46# turbine oil doped with 6wt%Mn0.78Zn0.22Fe2O4 nanoparticles show the best tribological properties among the tested oil samples, and PB value is increased by 26%, and the decreasing percentage of wear scar diameter is 25.45% compared to base oil.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marlene Bartolomé Sáez ◽  
Antolin E. Hernández Battez ◽  
Jorge Espina Casado ◽  
José L. Viesca Rodríguez ◽  
Alfonso Fernández-González ◽  
...  

Purpose The purpose of this paper is to study the antifriction, antiwear and tribolayer formation properties of the trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate ionic liquid (IL) as additive at 1 wt.% in two base oils and their mixtures, comparing the results with those of a commercial oil. Design/methodology/approach The mixture of the base oils used in the formulation of the commercial oil SAE 0W20 plus the IL was tested under rolling/sliding and reciprocating conditions to determine the so-called Stribeck curve, the tribolayer formation and the antifriction and antiwear behaviors. Findings The use of this IL as additive in these oils does not change their viscosity; improves the antifriction and antiwear properties of the base oils, making equal or outperforming these properties of the SAE 0W20; and the thickness and formation rate of the tribolayer resulting from the IL-surface interaction is highly dependent on the type of base oil and influence on the friction and wear results. Originality/value The use of this IL allows to replace partial or totally commercial antifriction and antiwear additives. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0179/


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