Study On Static Supporting Force And Lubricating Properties Of Magnetic Liquid

Magnetic fluid is a colloidal suspension of nanoscale magnetic particles dispersed in the carrier liquid and encapsulated by an appropriate surfactant.As a new lubricating material,the magnetic liquid can form the localized lubrication with a certain external magnetic field,which reduces the usage amount of lubricant and the pollution of the external environment.As a result,magnetic liquid has a wide range of applications in the field of lubrication.In addition to the excellent performance of lubrication,the magnetic fluid can also provide a certain amount of static supporting force,exhibiting great advantages to traditional lubricant.However,different intensities of magnetic field result in different capacities of static supporting and different properties of lubrication.In this paper,the distribution of permanent magnet with different arrangements were designed.Then,the magnetic field distribution of the sample surface was analyzed using magnetic field simulation software,and the static supporting force of different permanent magnet arrangement was tested in experiment.Meanwhile,the influence of the magnetic field distribution on the lubricating properties of the magnetic fluid was also studied.The conclusion of this paper are as follows:1.The arrangement of the permanent magnets determines the distribution of the magnetic field on the test surface.The magnetic fluid is concentrated in the strong magnetic field and its shape on the test surface is according with the result of the magnetic field simulation.2.In the absence of magnetic field,the magnetic liquid does not have a static supporting force;the application of the external magnetic field gives the magnetic liquid a static supporting force,and it increases with the increased number of permanent magnets.In the same number of permanent magnet,the magnetic liquid on the arrangement of same pole between adjacent permanent magnets,produced greater static supporting force in the arrangement than that on the arrangement of opposite pole between adjacent permanent magnets.3.The magnetic field has a great influence on the lubrication properties of the magnetic fluid.The existence of magnetic field under the low-speed transforms the friction pair from the mixed lubrication state into the hydrodynamic lubrication state.Compared with no magnetic field,under a load of 100 N and a speed of less than 100 rpm condition,the existence of magnetic field can make the magnetic liquid possess an excellent anti-friction effect.Whereas in a load of 100 N and a speed more than 100 rpm condition,the existence of magnetic field increase the friction coefficient.