Abstract:A pin-on-disc wear apparatus was used to carry out the tribological experiment of brass to investigate the effect of a magnetorheological (MR) fluid on the interfacial surface with and without magnetic field. A series of tests were performed at the loads of 20-100 N and rotating speeds of 127-425 r/min for 2 h. The friction coefficient and wear rate were monitored by the wear apparatus, while the microstructures of the worn surfaces were observed by scanning electron microscope (SEM). In addition, the chemical composition of worn surfaces was analyzed by energy dispersive X-ray spectroscopy (EDS). Test results show different friction and wear performance of the MR fluid with and without magnetic field. At the same time, the effects of various normal loads and rotating speeds on the tribological behavior were investigated. Through the investigation of the morphologies of the worn surfaces under the magnetic field, it is found that the MR particles are clearly evident on the worn surface and the plastic flow of ridges causes the lateral extrusion. This directly indicates that abrasive wear is the predominant wear mechanism observed with MR fluid.

Key words: magnetorheological fluid; sliding wear; brass; magnetic field; friction coefficient