Surface integrity evaluation in ecological nanofluids assisted grinding of Inconel 718 superalloy

Surface integrity is an important term that describes the surface behaviour of a ground component. Grinding is defined as a finishing operation that has high specific energy consumption. High heat generation while grinding, adversely affects the surface integrity of the ground surfaces. With the development of advanced materials such as superalloys, this process is widely used in bulk machining for making critical components used in dynamic loading. Therefore, it becomes necessary to investigate the surface integrity of the ground components, as their surface integrity primarily determines their performance and durability. The purpose of this work is to enhance the grinding performance of Inconel 718, a difficult-to-grind material, by employing silver and zinc oxide (ZnO)-based ecological nanofluids in a minimum quantity lubrication (MQL) mode. The grinding parameters such as wheel speed and table speed are kept constant with variations in the grinding infeed. The grinding performance in terms of grinding forces, apparent coefficient of friction, surface roughness and residual stresses on the ground surfaces have been investigated. Skewness, kurtosis and the Abbott-Firestone curve have also been analysed using two-dimensional and three-dimensional plots for an in-depth study of ground surface behaviour. The finding suggests that ZnO-based nanofluid outclass the silver-based nanofluid using MQL mode in terms of reduced grinding forces and favourable residual stress. Therefore, it appears as the potential grinding environment for the improved grinding performance of Inconel 718.