Preparation and abrasion properties of magneto-rheological fluid of dispersed silica-coated iron

摘要

In this study, a magneto-rheological fluid dispersed by silica-coated iron was developed and its properties such as fluid viscosity (shear stress or shear rate) and abrasion were investigated. The metallic iron coated by silica dispersed in magneto-rheological fluid was prepared by H-2 reducing of precipitated magnetite (Fe3O4). Then, the magneto-rheological fluid (MR fluid) for the seal was prepared with silica-coated iron or carbonyl iron (HQ type; diameter of 1.6-1.9 10(-6) m) and two solvent oils i.e. silicon oil (SH200cv, 10000cSt) and CVT oil (T-CVTF, automobile transmission oil). It was observed that the MR fluid viscosity of CVT oil with HQ particles is lower in every fluid condition. Furthermore, the surface roughness of polyvinyl plate after abrasion test for MR fluid with silica coated iron and CVT oil as solvent was higher compared to the other types of MR fluids. The results indicated that carbonyl iron (spherical particles) and silica-coated iron particles dispersed in silicon oil are feasible to be used where the low abrasion in mechanics is required.