International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 09 | Sep -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 1125 Experimental Investigation of Tribological Properties Using Nanoparticles as Modifiers in Lubricating Oil Mr. A.B. Najan 1 , Dr. R.R. Navthar 2 , Mr. M.J. Gitay 3 1,2 PG Scholar, Dept. of Mechanical Engineering, DVVP College of Engineering, Ahmednagar, Maharashtra, India 2 Professor, Dept. of Mechanical Engineering, DVVP College of Engineering, Ahmednagar, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Nanoparticles can be used as an additive in the engine oil to improve its tribological properties to reduce wear and friction of the engine. In this research molybdenum disulphide (MoS2) and copper oxide (CuO) nanoparticles are added to engine oil SAE20W50 and tribological properties are investigated. Samples were prepared of varying percentage of CuO and MoS2 nanoparticles in engine oil (0.25, 0.5 and 1 wt. %). The friction and wear tests were performed on DUCOM’s four ball tribotester and the tests were performed with varying concentration of nanoparticles in engine oil. Also viscosity tests were performed on Redwood viscometer for different samples at three different temperatures. The experimental observations show that MoS2, CuO nanoparticles added in engine oil exhibits good friction reduction and anti-wear properties and also decreased the coefficient of friction as compared with standard engine oil without MoS2, CuO nanoparticles. This tribological behavior is closely related to the deposition of nanoparticles on the rubbing surfaces Key Words: MoS2, CuO nanoparticles, tribological properties, engine oil, friction coefficient, wear 1. INTRODUCTION Nowadays nanoscience is one of the most expansively developing spheres of world’s science and its achievements can be applied in different areas of science and technology. Nanomaterials as an example which are in the form of so called nanostructures (nanotubes, nanowires, Nano powders and others) which are widely used in many human activity fields- from cancer treatment to engineered textiles or energy storage to rocket explosives and propellant . In upcoming decades various new fields of nanostructures application will arise. One of them seems to be the unexplored area of nanostructures use as additives modifying properties (especially tribological) of lubricating or cutting oils. Nanotechnology is regarded as the most revolutionary technology of the 21st century. It can be used in many fields of material science into a new era. In recent years numerous investigations have been carried out on the tribological properties of lubricants with different nanoparticles added in it. A number of papers from different authors all over the world have concluded that it is significantly effective to add nanoparticles to lubricant for reducing wear and friction. Among those that were added into oils, MoS2 nanoparticles have received much attention and exhibited excellent applications for their good friction reduction and wear resistance properties. The interfacial conditions which affect the reduction of wear are geometry, normal load, sliding speed, relative surface motion, surface roughness, vibration and lubrication. In addition, anti- wear properties, load-carrying capacities and friction reduction are mainly controlled by the chemical additives in lubricating fluid under boundary lubrication conditions. As the addition of a dispersing agent or the use of a surface modification preparation technique stabilizes the nanoparticles, inorganic nanoparticles have received considerable attention in the lubrication field. Nanoparticles have received considerable attention because of their special physical and chemical properties. The preparation of organic–inorganic complex nanoparticles was causing more interest in science and industry. However, few of them were used and studied as water base lubrication additives. In recent years, with the development of nanomaterial, many scientific researchers added nanoparticles into lubricating oils to improve extreme pressure, anti-wear, friction reducing properties, the efficiency and service life of machinery. The application of advanced nanomaterials has played an active role in improving and reforming traditional lubrication technology. The anti-wear mechanism of nanoparticles when they are used as additives in lubricants can be explained in three different ways: nanoparticles may be melted and welded on the rubbing surface, reacted with the specimen to form a protective layer, or tribo-sintered on the surface. However, some authors state that nanoparticles can also act as small bearings on the rubbing surfaces. Nanoparticles penetrate into lubricated EHD contacts to form a boundary film via mechanical entrapment influencing friction and wear. These nanoparticles are entrained into sliding contacts only when the film thickness is smaller than the particle size contributing to the film thickness. The above mentioned anti-wear mechanisms of the nanoparticles take place only under mixed and boundary lubrication. Results show that nanoparticles can improve the tribological properties of the base oil, displaying good friction and wear reduction characteristics even at concentrations below 1 wt%. However, they did not compare the tribological behavior of coated nanoparticles used as lubricant additives with the non-coated ones.