Antiwear and extreme pressure performance of castor oil with nano-additives

Author(s):  
Rajeev Nayan Gupta ◽  
AP Harsha

The aim of the present study is to examine the antiwear, antifriction, and extreme pressure performance of castor oil with nano-additives by using a four-ball tester. CeO2 (≈90 nm) and polytetrafluroethylene (≈150 nm) nanoparticles were used as an additive in castor oil with four different concentrations in the range of 0.1–1.0% w/v. The suspension stability of the nanoparticles was improved by using sodium dodecyl sulfate as a dispersant. Different analytical tools were used to characterize the nanoparticles parameter (i.e. shape and size) as well as the worn surfaces. The additive concentration was optimized on the basis of tribological performance. The test results of antiwear and extreme pressure property have been reported on the basis of wear scar diameter and weld load, respectively. For the antiwear test, it was observed that the maximum reduction in the wear scar diameter was 37.4 and 35.3% at an optimum concentration of CeO2 and polytetrafluroethylene additive, respectively. Also, antifriction and load carrying properties of castor oil were significantly improved with the addition of nanoparticles as an additive in a small amount. The mechanism for such improvement in the tribological behavior has also been discussed.

Lubricating oils containing ester, gaining more importance due to their friction reducing ability. Screening the performance of lubricating oils prior to field test is of most significance for the new lubricant formulations. In this endeavor, six lubricating blends were formulated having variable concentration of additives (sulfur and ester) in mineral oil and screened for their performance using four-ball tribo-tester. The formulated blends were evaluated for their extreme pressure and anti-wear characteristics as per ASTM standards. Tests were conducted on DUCOM TR- 30L four-ball tester and wear scar diameter were measured on an optical microscope.Compatibility and synergy of additives have been discussed on the basis of various parameters such as anti-wear scar diameter, mean scar diameter (just below weld load), mean scar diameter (at last non-seizure load), weld load and load wear index. The findings of this study demonstrate that ester along-with sulfur not only boost anti-wear properties but also enhance load carrying capacity of oil. An addition of sulfur beyond 2 % may not yield any significant improvement of tribo-characteristics of these oils.This paper is highlighting the synergistic effect of additives to render it as suitable lubricant for metal working applications. This paper also suggested an optimum concentration of an additive for its suitability for anti-wear and/(or) extreme-pressure properties.


2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Tarunendr Singh

The blends of bis(1,5-diaryl-2,4-dithiomalonamido)dioxomolybdenum(VI) complexes in lithium-base grease are evaluated for their extreme pressure activity in a “four-ball test” using 12.7 mm diameter alloy steel ball specimen. The additive, bis(1,5-di-p-methoxyphenyl-2,4-dithiomalonamido)dioxomolybdenum(VI) and bis(1,5-di-p-chloro-phenyl-2,4-dithiomalonamido)dioxomolybdenum(VI) exhibited lower values of wear-scar diameter at higher load and higher values of weld load, flash temperature parameter, and pressure wear index as compared with lithium-base grease without additives. The greases fortified with the developed additives prevent rusting and corrosion of bearings while grease containing no additives did not pass these tests as per the standard tests. These greases have also better oxidation protection as compared to the grease that has no additive. The topography and tribochemistry of the wear-scar surface are carried out by means of scanning electron microscopy and Auger electron spectroscopy techniques, respectively.


2018 ◽  
Vol 70 (3) ◽  
pp. 499-505
Author(s):  
Shanhua Qian ◽  
Hongyue Wang ◽  
Chuanhui Huang ◽  
Yongwu Zhao

Purpose This paper aims to modify carbon nanotubes with oleic acid, and to study the tribological properties of castor oil with modified carbon nanotubes additives. The proper additives are sought for the future engineering application of castor oil. Design/methodology/approach Tribological properties of the castor oils mixed with the modified carbon nanotubes of four mass percentages were investigated using a four-ball testing rig. Coefficient of friction and wear scar diameter were obtained in each test, and the mechanism of modified carbon nanotubes and castor oil was discussed. Findings The results indicated that modified carbon nanotubes had better dispersion in castor oil. Coefficient of friction first increased, then decreased and finally grew stable with the time, and wear scar diameter of steel surface functioned as a first reduced then increased change with the additive mass percentage of modified carbon nanotubes. The minimum of average coefficient of friction and wear scar diameter occurred at 0.02 Wt.% modified carbon nanotubes. Originality/value A small amount of modified carbon nanotubes could improve properties of the castor oil, and the mixed castor oil with 0.02 Wt.% modified carbon nanotubes would be most possibly used in engineering applications.


2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
Afifah, A. N. ◽  
Syahrullail, S. ◽  
Amirrul Amin M. ◽  
Faizal, H. M.

Since the last decade, vegetable oil has received tremendous attention as an alternative lubricant because of worsening state of environmental health and finite resources of mineral oil. However, the use of vegetable oil is restricted due to the poor low temperature fluidity and thermal-oxidative stability. These drawbacks can be enhanced by adding additive into the solution of vegetable oil. Thus, objective of this research is to investigate the influence of adding nanoparticle additive on tribological performance of palm kernel oil. The type of nanoparticle used throughout this study is copper oxide, which serves as anti-wear additive. Palm kernel oil (PKO), palm kernel oil-copper oxide nanoparticle (PKO-CuO), mineral oil (SAE-40), synthetic oil (SAE15W-50) are used as lubricant. Tribological properties if the used lubricants are evaluated using fourball tribotester under standard load and extreme pressure tests. Experimental results showed that the presence of nanoparticles in natural palm kernel oil improved tribological performances of friction and wear. The friction coefficient and wear scar diameter are reduced by approximately 5.0% and 3.5% respectively. The highest enhancement in friction coefficient value of ~20% was obtained under extreme pressure condition. Addition of nanoparticle also is found to improve load carrying capacity of PKO by 15%. 


2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Rajeev Nayan Gupta ◽  
A. P. Harsha

In the present study, tribological properties of castor oil have been investigated with and/or without use of additives by using four-ball tester. In the base castor oil, calcium–copper–titanate nanoparticles (CCTO) and zinc dialkyldithiophosphate (ZDDP) were added in different concentrations (i.e., 0.1, 0.25, 0.5, and 1.0 w/v%) to study their individual effect on tribological performance. Tribological test results have shown that there is an improvement in the antiwear, extreme-pressure (EP) properties at 0.25 and 1.0 w/v% for both the additives, respectively. However, in the coefficient of friction (COF) test (incipient seizure load), an optimum concentration of 0.5 w/v% was observed for ZDDP additive, whereas CCTO nanoparticles have shown similar level of performance at all concentrations. The worn-out surfaces were analyzed by using different analytical tools.


2013 ◽  
Vol 135 (4) ◽  
Author(s):  
R. B. Rastogi ◽  
J. L. Maurya ◽  
V. Jaiswal ◽  
D. Tiwary

Testing of lanthanum complexes of 1-aryl-2,5-dithiohydrazodicarbonamides of the formula LaL3 [LH=1-phenyl-2,5-dithiohydrazodicarbonamide(PhTHC), 1-methylphenyl-2,5-dithiohydrazodicarbon-amide(p-MePhTHC), 1-methoxyphenyl-2,5-dithiohydrazodicarbonamide(p-MeOPhTHC), 1-phenyl-2,5-dithiohydrazodicarbonamide(p-ClPhTHC)] for their application as extreme pressure lubrication (EPL) additives was performed on four ball tester using steel balls of 12.7 mm diameter and MoS2 as reference additive. The efficiency of the complexes has been evaluated using the tribological parameters, wear scar diameter, friction coefficient, initial seizure load, 2.5 s seizure delay load, weld load, mean Hertz load, flash temperature parameter and pressure wear index. The tested complexes behave as good extreme pressure additives; however, the best performance is shown by the p-methoxyphenyl derivative. The surface morphology of the wear scar on steel ball has been studied by atomic force microscopy and scanning electron microscopy. In presence of this complex, roughness of the worn surface is significantly reduced. The composition of wear scar has been analyzed by energy dispersive X-ray spectroscopy. The presence of lanthanum and sulfur in energy dispersive X-ray spectrum emphasizes role of additive in the tribofilm formed on the surface.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 386
Author(s):  
Haseeb Yaqoob ◽  
Yew Heng Teoh ◽  
Farooq Sher ◽  
Muhammad Ahmad Jamil ◽  
Mirza Nuhanović ◽  
...  

The four-ball tester was used in this analysis to demonstrate the lubricity of tire pyrolysis oil (TPO). The tribological performance of the tire pyrolysis oil was compared with diesel fuel (DF) and their blends, DT10 (TPO 10%, Diesel 90%) and DT20 (TPO 20%, Diesel 80%). A scanning electron microscope (SEM) was used to investigate the wear scar. In contrast to diesel fuel, TPO demonstrated better antiwear behaviour in terms of higher load-carrying capacity. DT10, DT20, and TPO’s wear scar diameter (WSD) was 22.35%, 16.01%, and 31.99% smaller than that of diesel at 80 kg load, respectively. The scanning electron microscope micrographs showed that the TPO and DT10 had less wear than their counterparts.


Author(s):  
E. S. Forbes ◽  
K. G. Allum ◽  
H. B. Silver

The surface topography and the nature of the surface layer of wear scars obtained with Bi(III), Pb(II), Cd(II), Ni(ll), and Zn(II) di-(4-methylpentyl-2) dithiophosphates, using the four-ball machine, have been studied using an electron probe microanalysis (EPMA) technique. The results show that the nature of the dithiophosphate markedly affects the surface topography, element content, and distribution of the wear scar in both the extreme pressure and mixed lubrication or antiwear regions. The implication of these EPMA results on the load-carrying mechanism of metal dialkyl dithiophosphates is discussed.


Author(s):  
Yi Zhang ◽  
Yan Luo ◽  
Jian-Qian Hu ◽  
Tao Zhang ◽  
Yun-Yun Xu

A four-ball tester was used to evaluate the tribological performance of bismuth diamyl-dithiocarbamate in mineral oil, and compared with same types of metal additives. The results show that it exhibits better load-carrying capacities than said organic metal additives. The surface analytical tools such as X-ray photoelectron spectrometer (XPS) and Scanning electron microscopy (SEM) were used to investigate the topography, the compositions contents and the depth profile of some typical elements on the rubbing surface of worn scar. Smooth topography of worn scar further confirms that the additive showed good antiwear capacities, the results of XPS indicated that tribochemical mixed protective films consists of bismuth compounds, sulfides, sulphates and metal oxides, which contribute to improve the tribological properties of lubricants. Particularly, a larger number of bismuth containing compounds play an important role in improving extreme pressure properties of oils.


Author(s):  
Jagadeesh K. Mannekote ◽  
Satish V. Kailas

Vegetable oils are increasingly used as lubricant base oils, because of sustainability issues and regulations. In present study coconut, palm, sunflower and castor oils were used to represent different levels of unsaturation, where as castor oil was selected to represent influence of hydroxyl group. The effect of oxidation on the boundary lubrication properties was evaluated by subjecting the oils to accelerated ageing at 333,353 and 373 k according to AOCS method. The experiments were carried out by using of four ball tester increase in observed wear scar diameter with temperature was more with oil having higher percentage of unsaturated fatty acids. At the same time it was also observed that increase in wear scar diameter with temperature was more with castor oil compared to other oil samples. The poor boundary lubrication properties observed with aged oil samples was possibly due to the deterioration of the triglyceride structure.


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