Characteristic Of Carbonyl Powdered Iron Magnetorheological Fluid & Its Preliminary Applied Research

Magnetorheological (MR) fluids are new intelligent materials that respond to an applied magnetic field with a change in their rheological properties. MR fluids of good properties will produce a distinct MR effect when magnetic strength comes to a value, which means the properties of fluids will change from liquid to solid instantly ,so does the opposite. In the absence of an applied magnetic field, MR fluids exhibit Newtonian-like behavior; Upon application of a magnetic field, MR fluids form a chain-like microstructure aligned with the direction of the applied magnetic field rapidly to increase the yield stress by holding back the flow of the MR fluids.In this dissertation,the present domestic and international research condition of MR fluids is analyzed ,and aspects which affect the performance of MR fluids contain physical performance, chemistry performance, mechanics performance, magnetics performance,rub characteristic,stabilize performance , the degree of viscosity and density ,and the mechanism of MR fluids is analyzed as well. The particles of MR fluids magnetize mutually subjiect to an applied magnetic field ,and form chain-like structure,consequently,increase the viscosity characteristic because of holding back the flow of MR fluids.Based on the characteristic of MR fluids , iron carbonylpowder is taked for suspension state ,and different additive form all kind of MR fluids together.Based on the working principle and process of viscosity test system made use of , the performance of iron carbonylpowder MR fluids is tested,consequently, the experiment data is analyzed under the different carrier fluid and different additive, consequently, the relations between viscosity with no magnetic field applied,shear stress and stability are compared. shear stress of the MR fluids mainly depends on magnetic field strength ,magnetized particles saturation,shear strain ratio and temperature ect.In this dissertation,base on the characteristic of iron carbonylpowderMR fluids , the yield stress of the MR fluids controlled by applied magnetic field and machine design combine together, the power transmission equation is estabilished, The geometrical design method is put forward to provide the theoretical foundation for the design of the MR clutch.