Hysteresis phenomena of ultrasonic velocity change in magnetorheological fluids

摘要

The magnetorheological response of magnetorheological fluids (MRF) results from the polarization induced in the suspended particles by application of an external magnetic field. We proposed a qualitative analysis of these effects by measuring properties of ultrasonic propagation. Hysteresis was appeared when magnetic field increased to and decreased from the certain value, 290 mT in our experiment. The change rate of the ultrasonic wave propagation velocity increased during the increasing process of the external magnetic field. However, it was kept almost the same value during the decreasing process.