Rheological behavior of magneto-rheological grease (MRG)

摘要

This paper presents an experimental study on the rheological properties of a magneto-rheological (MR) grease. MR fluids and MR greases are materials which consist of micron-size ferrous particles suspended in a carrier fluid. Their material properties such as apparent viscosity and shear stress can be altered dramatically and reversibly when stimulated by a magnetic field. The main difference between a MRG and a MR fluid is the viscosity of the carrier fluid. Unlike MR fluids, MRGs do not have the particle settling issue. The steady-shear magneto-rheological response of MRGs with at different temperatures is investigated. The results of apparent viscosity and yield stress under different applied magnetic fields are reported. In addition, the wall surface effect on the flow behavior of MRGs under different applied magnetic fields is examined using a slit channel flow device.