Disc testing apparatus and rheological performance of MR fluid

In order to obtain the yield shear stress of MR fluid in various magnetic fields, a disc testing apparatus with a digital electromagnetic system that can produce a maximal magnetic field as strong as 1.0 Tesla in the sample dish was designed and made. In addition, a good method to produce stability MR fluids without any hard sedimentation was presented and performance in and not in magnetic field of two kinds of MR fluid made by above method are studied and analyzed by the MR fluid testing apparatus and standard commercial rheometer. The results show that the higher the percent of magnetic particles is, the higher the yield shear stress and the saturation magnetic field of MR fluid are and the higher the viscosity of MR fluid is, the more easily the shear-thinning appears.