An Investigation on Wet Tribology of Dispersed Solid Lubricants in The Presence of Surfactant

Abstract

The use of solid additives to enhance the properties of lubricating oil has been gaining immense interest in various automotive and metal working applications, owing to a preference towards the modernization of mechanical components and their compatibility with the environmental friendly additives. These factors help in reducing the friction as well as wear, which in turn, facilitate the enhanced life of the mating parts and improved energy efficiency of systems. Various particles such as MoS2, WS2, Cu, CuO, graphite, hexa-boron nitride (h-BN), soot, graphene, diamond-like carbon (DLC), etc are being tested as potential oil additives. Recently, tribologists have concentrated on tubular structured solid additives such as carbon nanotubes (CNTs) because of their high aspect ratio, flexibility, and unique chemical, optical and mechanical properties. It is worth to mention here that the major obstacle for the usage of micro/nanoparticles in the tribological arrangements is their poor solubility and speedy agglomerate formation, which results in excessive wear and depletion in tribo performance. This problem can be handled by functionalizing the nanoparticles or using the surfactants and dispersants. In this context, it is worthwhile to mention that the target tribo-pair plays a prominent role in the selection and compatibility of particle additives for their potential utilization. To overcome some of the limitations associated with the use of Al-alloys in the tribological applications, the development of AMMCs are getting growing interest amongst the researchers. AMMCs are potential candidate materials for various applications due to their superior properties such as high specific strength and thermal conductivity, better corrosion and wear resistance, low cost, low coefficient of thermal expansion and high toughness.