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In today’s paradigm petroleum and petro-based chemical products are being extracted and consumed at a substantial rate, proving to be hazardous and detrimental to the earth. Bio based resources are environmentally friendly, energy efficient, economical, and proved to be an alternative to the present mineral oils. This paper documents the research on naturally available mahua seed oil for bio-lubrication, its flash point and fire point, tribological properties namely coefficient of friction and wear scar diameter have been modified by the addition of zinc oxide (ZnO) nanoparticles in different concentrations by weight percentage (0.25, 0.50, 0.75, and 1.0). four-ball tester was used according to ASTMD-4172 standards (60 min under 40 kg running at 1200 rpm). Probe ultrasonicator was used for particle dispersion. It was found that 0.75 wt. % loading of ZnO in mahua oil resulted in a 57.14% drop of coefficient of friction, but a slight increase in the wear scar diameter of 30.60% was observed.

In today’s paradigm petroleum and petro-based chemical products are being extracted and consumed at a substantial rate, proving to be hazardous and detrimental to the earth. Bio based resources are environmentally friendly, energy efficient, economical, and proved to be an alternative to the present mineral oils. This paper documents the research on naturally available mahua seed oil for bio-lubrication, its flash point and fire point, tribological properties namely coefficient of friction and wear scar diameter have been modified by the addition of zinc oxide (ZnO) nanoparticles in different concentrations by weight percentage (0.25, 0.50, 0.75, and 1.0). four-ball tester was used according to ASTMD-4172 standards (60 min under 40 kg running at 1200 rpm). Probe ultrasonicator was used for particle dispersion. It was found that 0.75 wt. % loading of ZnO in mahua oil resulted in a 57.14% drop of coefficient of friction, but a slight increase in the wear scar diameter of 30.60% was observed. [ABSTRACT FROM AUTHOR]

The addition of nanoparticles to lubricant is effective for the reduction of wear and friction in the mechanical system. In this research, the effects of additions of copper oxide nanoparticle nanoparticles on lubrication behavior of biodiesel-diesel fuel blends were investigated by using a four-ball tester. Three fuel blends with the addition of 0, 25, 50 and 75 ppm nanoparticle were tested in steady-state conditions at four different rotational speed of 600, 1200 and 1500 rev/min. the results showed that the friction coefficient decreases with the increase in nanoparticles up to 50 ppm because of filling the friction surface with the nanoparticles and replacement of sliding friction with the rolling effect in the contact zone. On the other hand, the FC was enhanced significantly with 75 ppm nanoparticle addition in fuel blends B10 and B20. However, the results showed that the lubrication of fuel blend B50 with the 75 ppm nanoparticle is better than that of other fuel blends in the same situation. Moreover, it was found that with an increase in biodiesel concentration the friction coefficient was reduced due to free fatty acids, monoglycerides, and diglycerides as the components of biodiesel.

Due to environment concern, the current lubricant such mineral oil-based lubricant is not environmentally friendly as it were not readily biodegradable and toxic. Therefore, the vegetable oil-based lubricant has been promoted in order to replace mineral oil-based. In this study, the performance of lubricant for six different ratios between RBD Palm Olein and Semi-Synthetic oil were tested in different loads and been discussed in different parameters including coefficient of friction, wear scar diameter, surface roughness, flash temperature parameter and wear worn surface. Four-ball tribotester machine used to evaluate performance of sample lubricants using ASTM D4172 standard. From the results, it shows that the sample lubricants for engine oil mixing with RBD Palm Olein reduce in 38% of coefficient of friction compared to pure engine oil. From overall of the results, the performance of lubricant was improved as RBD Palm Olein mixing with engine oil.

The extreme pressure (EP) behavior of grease is related to its additives that can prevent seizure. However, in this study following ASTM D2596 four-ball test method, the EP behavior of greases was modified without any changes to its additive package. A four-ball tester with position encoders and variable frequency drive system was used to control the speed ramp up time or delay in motor speed to demonstrate higher grease weld load and lower grease friction that were fictitious. A tenth of a second delay in speed ramp up time had showed an increase in the weld load from 7848 N to 9810 N for grease X and 6082 N to 9810 N for grease Y. Further increase in the speed ramp up time to 0.95 s showed that the greases passed the maximum load of 9810 N that was possible in the four-ball tester without seizure. The mechanism can be related to the delay in rise of local temperature to reach the melting point of steel required for full seizure or welding, that was theoretically attributed to an increase in heat loss as the speed ramp-up time was increased. Furthermore, the speed ramp up time increased the corrected load for grease X and Y. This resulted in lower friction for grease X and Y. This fictitious low friction can be attributed to decrease in surface roughness at higher extreme pressure or higher corrected load. This study suggests that speed ramp up time is a critical factor that should be further investigated by ASTM and grease manufacturers, to prevent the use of grease with fictitious EP behavior.

The addition of nanoparticles to lubricant is effective for the reduction of wear and friction in the mechanical system. In this research, the effects of additions of copper oxide nanoparticle nanoparticles on the lubrication behavior of biodieseldiesel fuel blends were investigated by using a four-ball tester. Three fuel blends with the addition of 0, 25, 50 and 75 ppm nanoparticle were tested in steady-state conditions at four different rotational speed of 600, 1200 and 1500 rev/min. the results showed that the friction coefficient decreases with the increase in nanoparticles up to 50 ppm because of filling the friction surface with the nanoparticles and replacement of sliding friction with the rolling effect in the contact zone. On the other hand, the FC was enhanced significantly with 75 ppm nanoparticle addition in fuel blends B10 and B20. However, the results showed that the lubrication of fuel blend B50 with the 75 ppm nanoparticle is better than that of other fuel blends in the same situation. Moreover, it was found that with an increase in biodiesel concentration the friction coefficient was reduced due to free fatty acids, monoglycerides, and diglycerides as the components of biodiesel. [ABSTRACT FROM AUTHOR]

The present work deals with the study of tribo-pair interaction in lubricated sliding contacts. By considering the environmental issues, the sunflower oil was extracted from the sunflower seeds and used as a base lubricant. The two types of the nanoadditives, i.e., CuO and CeO2, varying concentrations from 0.10 to 0.50% w/v were used to formulate the nanolubricants. The compatibility/synergism of the nanoadditives was examined from antifriction and antiwear behavior study with four-ball tester. Also, sunflower oil was modified by the chemical method to improve its fatty acid structure. A comparative tribological and compatibility study was also done in modified oil at similar concentration levels with both types of nanoparticles. The tribological test result exhibits 0.10% w/v concentration of the nanoadditive as optimum due to lowest wear scar and coefficient of friction. Higher concentration of the nanoparticles impaired the base oil performance. Different analytical tools were used to characterize the oil modification and worn surfaces. Moreover, the role of subsurface of the contacting material with the tribological performance has been reported. [ABSTRACT FROM AUTHOR]

Magnesium-doped zinc oxide (Zn0.92Mg0.08OO) (ZMO) nanoparticles of 23 nm particle size have been synthesized by auto-combustion method. The variation in particle size of these nanoparticles has been performed by their further calcination at 800 and 1000 °C for 2 h and the corresponding calcined particles are designated as ZMO-1 and ZMO-2, respectively. The nanoparticles have been characterized by powder-XRD, scanning electron microscopy (SEM), energy dispersive X-ray and transmission electron microscope. The effect of particle size on the antiwear lubrication behavior of paraffin base oil has been investigated on four-ball lubricant tester. The tribological tests of these nanoparticles as antiwear additives have been studied at an optimized concentration (0.5 %w/v) by varying load for 30 min test duration and by varying the test durations at 392 N load. Various tribological parameters such as mean wear scar diameter, friction coefficient (l), mean wear volume, running-in and steady-state wear rates show that these nanoparticles act as efficient antiwear additives and possess high load-carrying ability. From these tribological tests it has been observed that the lubrication behavior of studied nanoparticles is strongly sizedependent. The best tribological behavior is shown by nanoparticles of the smallest size, ZMO. Being sulfur, halogen and phosphorous free, ZMO nanoparticles have potential to be used as low SAPS lubricant additives. The SEM and atomic force microscopy analysis of the worn surfaces lubricated with ZMO nanoparticles at 392 N applied load for 60 min test duration show drastic decrease in surface roughness. The values of surface roughness of different additives are in good agreement with their observed tribological behavior. [ABSTRACT FROM AUTHOR]

Bio-oil from fast pyrolysis of biomass is a low-grade liquid fuel, which can be upgraded through the emulsification with diesel oil. In this study, we prepared two rice husk bio-oil samples with different solid char contents and three bio-oil/diesel-oil emulsion samples with the bio-oil content of 10 wt%, 30 wt% and 50 wt%, respectively. The lubrication properties of these oil samples were evaluated by a four-ball tester. The morphologies of the worn ball surface were observed by scanning electron microscope (SEM). The chemical states of the elements on the worn surface and non-worn surface were analyzed by X-ray photoelectron spectroscope (XPS). The results showed that the bio-oil possessed better extreme-pressure, anti-wear and friction-reducing properties than the commercial diesel oil (number zero). The solid char particles in the bio-oil could improve its lubrication performance. Moreover, the lubrication ability of the emulsions would be enhanced with the increasing of the bio-oil content in the emulsions.

Bio-oil from fast pyrolysis of biomass is a low-grade liquid fuel, which can be upgraded through the emulsification with diesel oil. In this study, we prepared two rice husk bio-oil samples with different solid char contents and three bio-oil/diesel-oil emulsion samples with the bio-oil content of 10 wt%, 30 wt% and 50 wt%, respectively. The lubrication properties of these oil samples were evaluated by a four-ball tester. The morphologies of the worn ball surface were observed by scanning electron microscope (SEM). The chemical states of the elements on the worn surface and non-worn surface were analyzed by X-ray photoelectron spectroscope (XPS). The results showed that the bio-oil possessed better extreme-pressure, anti-wear and friction-reducing properties than the commercial diesel oil (number zero). The solid char particles in the bio-oil could improve its lubrication performance. Moreover, the lubrication ability of the emulsions would be enhanced with the increasing of the bio-oil content in the emulsions. [ABSTRACT FROM AUTHOR]

The extreme pressure (EP) behavior of grease is related to its additives that can prevent seizure. However, in this study following ASTM D2596 four-ball test method, the EP behavior of greases was modified without any changes to its additive package. A four-ball tester with position encoders and variable frequency drive system was used to control the speed ramp up time or delay in motor speed to demonstrate higher grease weld load and lower grease friction that were fictitious. A tenth of a second delay in speed ramp up time had showed an increase in the weld load from 7848 N to 9810 N for grease X and 6082 N to 9810 N for grease Y. Further increase in the speed ramp up time to 0.95 s showed that the greases passed the maximum load of 9810 N that was possible in the four-ball tester without seizure. The mechanism can be related to the delay in rise of local temperature to reach the melting point of steel required for full seizure or welding, that was theoretically attributed to an increase in heat loss as the speed ramp-up time was increased. Furthermore, the speed ramp up time increased the corrected load for grease X and Y. This resulted in lower friction for grease X and Y. This fictitious low friction can be attributed to decrease in surface roughness at higher extreme pressure or higher corrected load. This study suggests that speed ramp up time is a critical factor that should be further investigated by ASTM and grease manufacturers, to prevent the use of grease with fictitious EP behavior. [ABSTRACT FROM AUTHOR]