Effect Of Magnetic Field On Friction Surface Behavior Of Materials With Different Magnetic Properties

In the face of increasingly severe resource and energy problems,a higher requirement of the service life and stability of the mechanical and electrical equipments is needed,more and more researchers pay attention to the effects of work environment on friction and wear performance of the moving parts.With the development of magnetic technology,a growing number of friction pairs work in magnetic field,it becomes very necessary to study the influences of magnetic field on friction and wear properties of materials.The effect of magnetic field generated by current coil on dry sliding friction and wear properties of ferromagetic material 45 steel couple,diamagnetic material H62 brass couple and 45 steel pin-H62 brass ring couple were researched on a home-made wear tester with a pin-on-ring contact style.The worn surface and wear debris were mostly analyzed by using Scanning Electron Microscope,X Ray Diffractometer,3D Profiler and Transmission Electron Microscope.The main conclusions in this paper are as follows:For 45 steel-45 steel couple,magnetic field decreases the wear rate,while increases the friction coefficient.The magnetic field promotes the oxidation of worn surface and wear debris as well as the refinement of wear debris,changes the way that wear debris participates the process of friction and wear,indirectly increases the proportion of oxidative wear in the wear process.In addition,the magnetic field accelerates the formation of an isolation layer between the wear surfaces so as to avoid the direct contact of the surfaces,which is the main reason to change the friction and wear properties of ferromagnetic materials.For H62 brass-H62 brass couple and 45 steel-H62 brass couple,magnetic field decreases both the wear rate and the friction coefficient.The magnetic field has no obvious influences on the oxidation of worn surface and wear debris as well as the particle size of wear debris of diamagnetic material H62 brass.The magnetic field even has a repulsive force on the diamagnetic materials so as to promote separation of daimagnetic wear debris from the wear surfaces and make the wear surface contact more directly,which is the main reason to increase the friction and wear of diamagnetic materials.For 45 steel-45 steel couple,when magnetic field exists,there are more debrisbetween the wear surfaces,the wear rate is decreased;when compressed air is used to remove the wear debris,the wear rate is increased.In the process of dry friction,moderate wear debris existing between the wear surfaces is a result of self adjusting of the dry friction system,the number of debris between the wear surfaces is related to the contact state of the wear surfaces,which is the main reason to influence the friction and wear properties of materials.The effect of magnetic field on friction and wear is related to the magnetic properties of materials,magnetic field increases the abrasion resistance of ferromagnetic materials and decreases the abrasion resistance of diamagnetic materials.