Tribological Properties of New Developed Nano Boric Acid Suspended as Additive in Engine Oil

Abstract

It is well known that nanoparticles affect the interaction between lubricants and surfaces with various chemical compositions and different chemical and physical properties. In recent years, nanoparticles have started to play more important roles as lubricant additives for their potential in wear, friction and emission reduction and improving lubrication and fuel economy. Although nanolubricants are frequently used for friction tests, little is known about stability and degree of dispersion of these nanoparticles in viscous liquids. Most of them are unstable, agglomerate or aggregate which sediment over time. Boric acid (H3BO3) has always been a very important material due to its broad range of applications such as in medicine, cosmetics, automotive industry, metallurgy and also for miscellaneous purposes in other areas. Literature survey showed that friction between automobile engine parts could be greatly reduced using microscopic particles of boric acid.This study involves the new invention of successful suspension of nano boric acid (BA) additive added into 5W-40 fully synthetic commercial lubricating oil. This invention is confidential and realized by Murat ÖZAYMAN from Tribor ARGE Co. in Teknopark of YILDIZ Technical University in Istanbul-TURKEY. The particle size of BA is determined with (Transmission Electron Microscopy) (TEM). Backscattering and transmittance profiles proved that nano boric acid (BA) particles were in suspension in commercial engine oil. Suspended BA in engine oil is applied between piston ring and cylinder liner system in order to investigate their effect on friction and wear under boundary lubricated conditions. Simulation and measurement of friction and wear were conducted using a reciprocating tribometer. Surface analysis were performed using 3D digital optical microscope, Field Emission Scanning Electron Microscope (FESEM)/X-Ray, X-ray photoelectron spectroscopy (XPS) and Atomic Force Microscopy (AFM). Boron (B) from BA is well detected, mixed with other elements of additives and protected the surface under boundary lubrication conditions. The results indicate that BA can considerably improve the tribological performance of a piston ring and cylinder liner system under lubricated conditions. It has found that the friction coefficient is reduced with nano boric acid (BA) suspended engine oil and protected the surface mostly on cylinder liner mixing with other additives.