Experimental evaluation on the tribological properties of coconut oil by the addition of CuO nanoparticles

Abstract

Considering the environmental problems created by mineral based lubricants, exploring the possibility of the use of vegetable base oils as automobile lubricants has been a growing worldwide trend. In the present study, analysis of coconut oil as a lubricant has been carried out in the perspective of its tribological behaviour using a pin-on-disc tribometer. Copper oxide nanoparticles are added to the oil on weight-percentage basis, the variation of its friction-reduction and antiwear properties are analysed. At an optimum concentration of nanoparticles, the coefficient of friction and the specific wear rate are found to be the lowest. Viscosity of oil is also seen to increase by an increase of concentration of nanoparticles. Flash-point remains constant while the fire-point increases as the nanoparticle concentration is increased. From dispersion analysis it is seen that the nano oil is not suitable enough for long stationary applications. Surface structure of the worn surfaces obtained by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) shows that the optimum concentration of nanoparticles in this lubricant causes the roughness of the worn pin surface to reduce to a low value after sliding. Wear scar obtained in the presence of nano oil is smoother compared to that with bare coconut oil. When the level of nanoparticles increases above the optimum level, friction coefficient and wear rate are seen to increase.

Copper oxide nano-particles as friction-reduction and anti-wear additives in lubricating oil

“…Various types of nanoparticles have been used to prepare nano lubricants, including polymers, metals, organic and inorganic materials [2]. Copper oxide nanoparticles are also being investigated by some researchers in context of their tribological and anti-wear properties [3,4]. Vadiraj et al investigated the effect of nano boric acid and nano copper based engine and transmission oil additives in different volume ratios (1:10, 2:10, and 3:10) on friction and wear performance of cast iron and case carburized gear steel [5].…”

Morphology dependence of thermal and rheological properties of oil-based nanofluids of CuO nanostructures

“…The flash point is another important factor in oil based nanofluids determining the safety scales of nanofluids. Some studies have revealed that nanofluids prepared using CuO nanoparticles have special tribological properties compared to many other additives [7,8], so are suitable to be used in nanolubricants. In the present work, different CuO nanostructures have been fabricated and effect of various morphologies on the thermal conductivity, viscosity and flash point of CuO-oil based nanofluids have been investigated.…”

Effect of Nano and Micro Friction Modifier Based Lubricants on Wear Behavior Between Steel-Steel Contacts

“…All pins were cleaned with acetone and dried before and after tests. Oil was supplied drop by drop at the interface in order to maintain thin film lubrication/boundary lubrication [18]. Each test was performed three times and the average value of the test has been shown in this work.…”