Preparation of Reduced Iron Powders Magneto-Rheological Fluid Using Iron Scale

Iron scale of the rolled steel was solved by H2SO4,and FeSO4 solution was got after purification.Then α-Fe2O3 powders were prepared by precipitation method using (NH4)2CO3.After α-Fe2O3 was reduced by H2,the reduced iron powders were mixed with some silicone oil and a little nano Fe3O4 to prepare reduced iron powders magneto-rheological fluid(MRF).The reduced iron powders were characterized and the properties of the powders and MRF were studied.The results show that the particle size of reduced iron powders was about 1 μm and the specific saturation magnetization was the same as carbonyl iron powders.The reduced iron powders MRF belonged to Binham fluid and the shear stress could increase effectively by adding 0.8wt% nano Fe3O4.The reduced iron powders MRF not only had good anti-sedimentation stability,but also superior magneto-rheological properties in low magnetic field intensity.