Nanosized m olybdenum disulfide on surface‐modified carbon material as lubricating oil additive for friction‐reduction and anti‐wear

2021 ◽  
Author(s):  
Huaigang Su ◽  
Chencan Li ◽  
Cheng Jiang ◽  
Yanan Wang ◽  
Xiaobo Wang ◽  
...  
2009 ◽  
Vol 79-82 ◽  
pp. 1863-1866 ◽  
Author(s):  
Shi Yu Ma ◽  
Shao Hua Zheng ◽  
Hai Yang Ding ◽  
Wei Li

In this paper, the author does research on the surface modified of nanometer ZrO2/SiO2 composite and makes it a good dispersivity in organic solvents. As lubricating oil additive, added it into the base oil with different concentration. Anti-wear and reducing friction performances measured by the four ball test and the thrust-ring tribotester. The results showed that the average friction coefficient decreased 21.14%, the weight lost of the thrust-ring was no wear or negative wear when the additive concentration was 1wt%. The worn surfaces were quite different compared without additive, the grooves formed during the friction experiment become smooth and finally a narrow wear scar. There were many white particles and dimples on gray surface, the white particles were higher than those of gray parts. The white particles was ZrO2/SiO2 composites according to EDS and XRD analysis. The Si and Zr elements appeared on the worn surfaces can not be cleaned out in petroleum ether and ultrasonic ambiance, this is a dynamic self-healing mechanism .


2011 ◽  
Vol 328-330 ◽  
pp. 203-208 ◽  
Author(s):  
Cheng Bin Chen ◽  
Da Heng Mao ◽  
Chen Shi ◽  
Yang Liu

Nano-WS2(tungsten disulfide nanoparticles)lubricating oil additive, prepared by the nanometer WS2particulates and semi-synthetic engine base oil as raw materials, was added into Great Wall engine oil with different mass ratio. With a contrast study on these oil samples, the results show that it can improve the extreme pressure, antiwear and viscosity-temperature properties of the engine oil effectively by adding a certain amount of nano-WS2additive, and the optimal concentration is 2wt%. The oil film strength, sintering load and viscosity index of this lubricating oil is respectively 1.35 times, 1.58 times and 1.05 times as that of Great Wall engine oil. In addition, when tested under the grinding conditions of 392 N, 1450 r /min and 30 min, the diameter of worn spot reduces 0.018mm, and the average friction coefficients of friction pairs decrease 16.3%, both of which are lubricated by the oil containing nano-WS2additive. Meanwhile, the experiments testify that the tribological and viscosity-temperature properties of the nano-WS2additive are better than that of the Henkel MoS2additive.


RSC Advances ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 4595-4603 ◽  
Author(s):  
Xinhu Wu ◽  
Kuiliang Gong ◽  
Gaiqing Zhao ◽  
Wenjing Lou ◽  
Xiaobo Wang ◽  
...  

Red phosphorus (P) was covalently attached to graphene nanosheets (Gr) using high-energy ball-milling under a nitrogen atmosphere.


Author(s):  
Thomas Brinkmann ◽  
Jens Gaertner ◽  
Klaus Gebauer

The reduction of friction in the valve train of four-stroke combustion engines is a promising opportunity to decrease fuel consumption and to improve pollutant emissions. The possibilities are reviewed by comparing light weight and newly developed components. The friction in the valve train causes a loss from the BMEP by about 0.2 to 0.4 bar. To measure friction forces in this range requires constant and well maintained environmental conditions. The viscosity as well as the pressure and temperature of the lubricating oil have a big influence on the friction. Due to the valve spring forces a strong fluctuation of the cam torque appears. This makes it very demanding to set up the measurement equipment in a correct way. Measurement equipment which is able to gauge with sufficient accuracy may be overloaded by the effects caused by the spring forces. Based on this special care is necessary during the first ramp up of the cylinder head. It has to be modified to avoid overloading the measurement equipment. One possibility to achieve lower friction between the valve stem and the valve guide is the reduction of the lateral forces which are caused by the asymmetry of the valve spring. Using recently new developed components these detrimental forces within a valve train can be reduced which leads to lower friction losses. In addition the wear between the valve train components can be reduced. In detail this can be accomplished by using two-piece spring retainer which allows a tilted position of the spring end during the valve lift and by this only allow axial forces to act onto the valve. The friction in a valve train using a direct acting mechanical tappet is mainly caused by the sliding contact of the cam on the tappet face. To lower the friction in this area the spring forces have to be reduced. This requires valve train components with lower masses and weaker springs. Therefore valves, spring retainers and tappets made from light weight alloys where developed. The mass of these light weight components could be reduced by more than 50%. Detailed measurements are performed and the results will be presented. As a conclusion it can be seen, what light weight components in the valve train of four stroke engines can contribute to a torque reduction in innovative valve trains.


2019 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Na Wu ◽  
Ningning Hu ◽  
Jinhe Wu ◽  
Gongbo Zhou

The microscale/nanoscale lamellar-structure WS2 particles with sizes of 2 µm and 500 nm were synthesized by solid-phase reaction method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The synergies between microscale/nanoscale WS2 particles and ZDDP as lubricating oil additives was evaluated by means of UMT-2 tribometer at room temperature. The wear scars were examined with SEM and electron-probe micro-analyzer (EPMA). The results show that the anti-wear properties were improved and the friction coefficient was greatly decreased with the simultaneous addition of WS2 particles and ZDDP, and the largest reduction of friction coefficient was 47.2% compared with that in base oil. Moreover, the presence of ZDDP additive in the lubricant further enhances the friction-reduction and anti-wear effect of microscale/nanoscale WS2. This confirms that there is a synergistic effect between WS2 particles and ZDDP.


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