Magnetorheological characterisation of carbonyl iron based suspension

Purpose: The main aim of this article was to present the investigation results of magnetorheological fluids (MR) composed of carbonyl iron (CI) particles and analyse their flow behaviour in terms of the internal structure formation by a control of applied external magnetic field. The morphology, magnetic properties, sedimentation stability, and magnetorheological properties of the examined MR fluids were studied. Design/methodology/approach: Model MR fluid was prepared using silicone oil OKS 1050 mixed with carbonyl iron powder CI. Furthermore, to reduce sedimentation Aerosil 200 was added as stabilizers. In the purpose to determine the properties of the analyzed fluids the sedimentation and dynamic viscosity were investigated. Findings: Dynamic viscosity of investigated magnetorheological fluids rapidly and reversibly change in response to the applied external magnetic field. Moreover added particles of fumed silica inhibited sedimentation of carbonyl iron particles. Research limitations/implications: MR fluids with excellent properties can be applied in various fields of civil engineering, safety engineering, transportation and life science. They offer an outstanding capability of active control of mechanical properties. But there are no systematic published studies of factors affecting the durability of MR fluids and devices. There is very little information on the effects of exposing different MR fluids to temperature, for this reasons further efforts are needed in order to obtain even better results. Originality/value: The investigation results are reliable and could be very useful both for designers and the practitioners of many branches of industry.