Performance of hydraulic oils and its additives in fluid power system: A review

Abstract

The main objective of this paper is to analyze various hydraulic oils and the effect of additives like nanomaterials in order to increase lubricity, counter friction, reduce wear, etc. A detailed list of additives is focused in this review which will enhance the performance and working of the hydraulic fluid by enhancing lubrication, modifying viscosity and cleaning engine deposits. Mineral oils or Synthetic hydrocarbon blends are used to derive lubricants. Although they lack properties of their own to fulfill the requirements set by the Original Equipment Manufacturers (OEMs). By using nanomaterials in mineral oils various advantages can be obtained. Various nanomaterials such as metal chalcogenides, soft metals, carbon-based materials, etc. are available which via mechanisms such as the rolling effect, protective film effect, etc., can change the various properties of hydraulic oils as required. Similarly, additives are added to hydraulic oils like viscosity index improvers, anti-wear agents which will improve the properties of the hydraulic oil by eliminating negative properties and improving the life of the fluid. These additives play a crucial role in sustainability of hydraulic oils and their size can be optimized to get better tribological characteristics. The increasing usage of these high performance additives in the country is projected to register a compound annual growth rate (CARG) of more than 1.5% during the forecast period (2021-2026). The review focusses on the improved performance of these nanomaterials and additives when added to the Hydraulic Fluid and will serve as a reference for future developments in the application of additives and nanotechnology in hydraulic oils.