Magnetorheological fluids with stearate and thiophosphate additives

摘要

A magnetorheological fluid (MRF) comprises (wt.%): hydrocarbon-based liquid (10 - 14 or 5 - 25); bimodal magnetizable particles (75 - 95 or 86 - 90); fumed silica (0.05 - 0.5); and liquid mass of an additive package including a stearate and a thiophosphate (0.5 - 5). A magnetorheological fluid (MRF) comprises (wt.%): hydrocarbon-based liquid (10 - 14 or 5 - 25); bimodal magnetizable particles (75 - 95 or 86 - 90); fumed silica (0.05 - 0.5); and liquid mass of an additive package including a stearate and a thiophosphate (0.5 - 5). The bimodal magnetizable particles consist of a first group and second group of particles having a first and second range of diameter sizes with first and second mean diameters having standard deviation no greater than about two-thirds of the value of the first and second mean diameters respectively, such that the major portion of all particle sizes fall within the range of 1 - 100 mu m. The weight ratio of the first group to the second group is 0.1 to 0.9. The ratio of the first mean diameter to the second mean diameter is 5 - 10.