Sliding wear behaviour of micro-sized Kota stone dust reinforced epoxy composites using Taguchi method and Grey Wolf optimisation algorithm

Abstract

Kota stone dust (KSD) is an unwanted material engendered throughout the process of manufacturing Kota stone. The present work comprises the appropriate consumption of KSD for evolving a composite system with epoxy as the base matrix material. The samples are developed by the hand lay-up technique. The micrographs clearly show that KSD is uniformly distributed within the epoxy matrix and establishes good adhesion with it. With the inclusion of filler, density unwillingly increases by 21.86%, but voids generated are limited to only 4.98% for a maximum filler content of 40 wt. %. A very low water absorption rate of 0.81% for maximum filler loading is observed. The compressive strength and micro-hardness increased by 31.8% and 26.25% respectively. Tensile strength, as well as flexural strength, improves for low filler loading of 20 wt. % and decreases thereafter. The sliding wear tests of the fabricated composites are studied in this research employing fairly advanced nature-inspired Grey wolf optimisation (GWO). The wear tests are based on a real-world issue that is framed in Taguchi L₂₅ OA. A simple linear regression equation demonstrates adequate agreement between predicted and experimental values. The inclusion of KSD decreases the wear rate. Further, it is found that the KSD loading is the utmost significant factor, whereas normal load is the least significant factor that administrates the sliding wear rate of the composite system. Using the grey wolf optimiser, the optimal settings are 2500 m sliding distance, 40 wt.% KSD content, 52 cm/s sliding velocity, and 10 N normal load. The validation test results suggest that GWO is superior to the classical Taguchi approach. The wear loss mechanism is examined under the scanning electron microscope.