Wear and Friction Characteristics of Magnetorheological Fluid under Magnetic Field Activation

In this article, wear and friction characteristics of a magnetorheological (MR) fluid were studied under different magnetic fields. Using a pin-on-disc tribometer, the wear loss and friction coefficient were obtained with and without a magnetic field. The friction and wear of three typical materials under magnetic field were investigated at various normal loads and rotating speeds. After the wear tests, the worn surfaces of specimens were observed using a scanning electron microscope (SEM) in order to investigate the wear mechanisms, and the contacting surfaces were analyzed by energy-dispersive X-ray spectroscopy (EDS) to investigate the variation of elemental composition on the worn surface. Test results showed that the MR fluid exhibits better tribological characteristics under a magnetic field compared to the case without a magnetic field. The general morphology of the MR particles and wear debris was observed to assist with the analysis of friction and wear. The SEM micrographs and EDS spectra of the worn surfaces showed that the predominant wear mechanism in the case of the steel and brass specimens was abrasive wear by asperities and MR particles on the worn surfaces, whereas a mixed wear mechanism that included adhesive wear and abrasive wear was observed in the case of the aluminum specimen.