Friction and wear properties of core-shell (CI is a core & GO is a shell) particles based magnetorheological fluid under steel on steel point contacts

Abstract

This work is concerned with the experimental investigation of tribological and rheological properties of core–shell (carbonyl iron is the core and graphene oxide is the shell) particle-based MR fluid. Carbonyl iron (CI) particles were encapsulated with graphene oxide (GO) by a simple wet stirring process. The surface morphology, structural properties, and magnetic properties of graphene oxide encapsulated CI particles were analyzed by Field Emission Spectroscopy (FE-SEM), Raman Spectroscopy, and Vibrational Sample Magnetometer (VSM). The rheological properties of prepared samples were examined on a modular compact rheometer. The CI@GO particle-based MR fluid exhibited lower yield stress compared to bare CI particle-based MR fluid. Tribological tests of developed MR fluid were conducted on a universal tribometer with and without the presence of a magnetic field to ascertain the friction and wear behaviour. Experimental results revealed that the tribological properties are significantly improved by using CI@GO-based MR fluid in comparison to bare CI-based MR fluid and dry sliding conditions. Further, the wear analysis of worn surfaces was observed on FE-SEM, Energy-Dispersive X-ray Spectroscopy (EDS), and 3D-profilometer before and after each test. Three body abrasion wear mechanism was observed with some ploughing and groove formation.