Experimental evaluation of MoS2 nanosheets as lubricant additive in different types of base oil for magnesium alloy/steel pairs

2019 ◽  
Vol 6 (6) ◽  
pp. 066575 ◽  
Author(s):  
Xie Hongmei ◽  
Jiang Bin ◽  
Tang Changping ◽  
Dai Jiahong ◽  
Quan Xin ◽  
...  
2015 ◽  
Vol 87 ◽  
pp. 930-940 ◽  
Author(s):  
Yanbin Zhang ◽  
Changhe Li ◽  
Dongzhou Jia ◽  
Dongkun Zhang ◽  
Xiaowei Zhang

2019 ◽  
Vol 20 (3) ◽  
pp. 7-13
Author(s):  
Rusul F. Abdul-saheb ◽  
Muhanned A. Mohammed

In this study, the effects of blending the un-branched acrylate polymer known as Poly (n-decyl acrylate), and the branched acrylate polymer known as Poly (iso-octyl acrylate), on the viscosity index (VI), and the pour point of the Iraqi base stocks 40, and 60 respectively, were investigated. Toluene was used as a carrier solvent for both polymer types. The improvement level of oils (VI, & pour point) gained by blending the oil with the acrylate derived polymers was compared with the values of (VI, and pour point) gained by blending the oil with a commercial viscosity index, and pour point improver. The commercial lubricant additive was purchased and used by Al-Daura Refineries. It consisted of an un-known olefin copolymer dissolved in an un-known carrier solvent. All polyacrylate derivatives and the commercial lubricant additive named HITEC5748 were blended with each type of oil in weight percentage of (2, 4, 6, 8, & 10) wt. %. The result of the study was that the improvement in the viscosity index and the pour point of both base stock types was higher when using the polyacrylate derivatives than when using the commercial olefin copolymer additive.


2011 ◽  
Vol 239-242 ◽  
pp. 2233-2239
Author(s):  
Zhi Qian Chen ◽  
Wen Bin Yu ◽  
Mei Tao Ouyang

The formulation design and fundamental experiments of O/W type emulsions as lubricant and coolant in the hot rolling process of magnesium alloy were conducted in this work. The main components of emulsion were determined by the comparision of some candidates of base oil, polar oil additive and emulsifier in microstructure and properties, respectively. It is found that the conservation stability of emulsions is mainly dominated by the emulsifier concentration and type. The results showed that the suitable stability and microstructure was obtained by using compound emulsifier of nonionic and anionic surfactants. The feasible contents of both emulsifier and polar agents are about 10 percent, respectively.


2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Rupesh Roshan ◽  
Martin Priest ◽  
Anne Neville ◽  
Ardian Morina ◽  
Xin Xia ◽  
...  

Theoretical studies have shown that in severe operating conditions, valve train friction losses are significant and have an adverse effect on fuel efficiency. However, recent studies have shown that existing valve train friction models do not reliably predict friction in boundary and mixed lubrication conditions and are not sensitive to lubricant chemistry. In these conditions, the friction losses depend on the tribological performance of tribofilms formed as a result of surface–lubricant additive interactions. In this study, key tribological parameters were extracted from a direct acting tappet type Ford Zetec SE (Sigma) valve train, and controlled experiments were performed in a block-on-ring tribometer under conditions representative of boundary lubrication in a cam and follower contact. Friction was recorded for the tribofilms formed by molybdenum dithiocarbamate (MoDTC), zinc dialkyldithiophosphate (ZDDP), detergent (calcium sulfonate), and dispersant (polyisobutylene succinimide) additives in an ester-containing synthetic polyalphaolefin (PAO) base oil on AISI E52100 steel components. A multiple linear regression technique was used to obtain a friction model in boundary lubrication from the friction data taken from the block-on-ring tribometer tests. The model was developed empirically as a function of the ZDDP, MoDTC, detergent, and dispersant concentration in the oil and the temperature and sliding speed. The resulting friction model is sensitive to lubricant chemistry in boundary lubrication. The tribofilm friction model showed sensitivity to the ZDDP–MoDTC, MoDTC–dispersant, MoDTC–speed, ZDDP–temperature, detergent–temperature, and detergent–speed interactions. Friction decreases with an increase in the temperature for all ZDDP/MoDTC ratios, and oils containing detergent and dispersant showed high friction due to antagonistic interactions between MoDTC–detergent and MoDTC–dispersant additive combinations.


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.


Author(s):  
M Kaneta ◽  
T Ogata ◽  
Y Takubo ◽  
M Naka

The effects of the thickener structure and base oil viscosity on the grease film formation in rolling point elastohydrodynamic contacts have been discussed on the basis of direct observation using the optical interferometry technique. Three different types of diurea greases without additives have been used as test greases. As the base oils three kinds of ether-type synthetic oils having similar molecular structures but different viscosities were used. The film behaviour of fresh greases has also been compared with that of the degraded greases. It has been found that the behaviour of grease elastohydrodynamic lubrication films is basically influenced by the thickener structure and base oil viscosity. The adhesion or deposition of the thickener on the contacting surfaces and oil starvation which affect film formation depend on the thickener structure, base oil viscosity and rolling speed. Furthermore, it has been suggested that there is an optimum temperature which gives a maximum film thickness according to the consistency of the grease.


2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Flavio A. C. Vidal ◽  
Antonio F. Ávila

A top-down approach is employed to investigate the tribological effect of adding nanographite platelets (NGPs) to mineral base oil (MBO). The performance of the NGP-modified MBO was evaluated by examining the friction and anti-wear properties. Four different types of NGPs produced by two different processes were employed. The optimal NGP-modified MBO attained a significant wear and friction reduction when compared with the MBO without NGPs. The process used to exfoliate the graphite nanoplatelet samples provided better wear properties because of the graphene layers' smoother sliding mechanism. Graphene layers seeped inside the groove marks to keep the friction coefficient low.


Sign in / Sign up

Export Citation Format

Share Document