INFLUENCE OF POLARIZATION RATE AND DIELECTRIC LOSS ON ER EFFECTS

A simplified model is considered to describe the resistive transport and diffusion of charge carriers within or around an ER active particle under influence of AC electric field and temperature. The effective polarization strength, dielectric constant and dielectric loss of the particle are derived from this model. Considered the effects of shear field, the criteria for ER activity are presented as ωτ >10-4, 1dielectric loss of ER particles. The criteria are testified by the following experimental results. First, the measured lower limit of diatomite particle conductivity is 7.3×10-8S/m. Second, the shear stresses at the shear rates from 9.9 to 100s-1 at 1kV/mm field start to rise with temperature from 25°C. Third, with decreasing shear rate or/and increasing electric field strength, the peaks of shear stress shift down the lower temperatures.