The Effects Of Horizontal Magnetic Field On Wear Debris Behaviors And Vibration And Noise Characteristics On Sliding Friction Interface

The unstable vibration and noise produced in the friction process have some considerable and negative impacts on industry production and humans' lives.Researchers have conducted many studies about the friction-induced vibration and noise to find some methods for the reduction of vibration and noise.Some researchers have found that the friction interface modification,friction materials,system parameters and friction environment can affect the friction-induced vibration and noise.Among these impact factors,the former three factors may change the friction system and friction status while the friction environment not.Moreover,the magnetic field as an environmental factor was found can affect the friction and wear.Considering the correlations among friction,wear,vibration,and noise,magnetic field may also affect the friction-induced vibration and noise.Therefore,researching the characteristics of vibration and noise under the magnetic field,exploring the effect of magnetic field on vibration and noise,and applying the magnetic field on the reduction of vibration and noise are very innovative.This study has great theoretical guidance and practical significance for exploring the method for the reduction of vibration and noise.In this study,a setup was designed to provide stable magnetic field based on the traditional friction and wear machine.Ball on disc tests were subsequently conducted on three friction pairs,namely,steel-aluminum alloy,SiC-forged steel,and steel-forged steel pairs.The mechanisms of magnetic field affecting friction-induced vibration and noise were studied by analyzing the differences in wear debris accumulation behaviors.The ability of a horizontal magnetic field in reducing vibration and noise was found after the tests.Then,the approaches of blowing air and adding a magnetic field were proposed to reduce vibration and noise by cleaning up wear debris.The friction tests under these two approaches were conducted separately and the effects of two approaches on vibration and noise reduction were compared.The differences of the effect of these two approaches are discussed further.The main conclusions are as follows:1.For the tests of magnetic field affecting vibration and noise of three friction pairs,the presence of a magnetic field can clearly reduce the friction-induced vibration and noise of steel-forged steel,but yielded no significant effects on these signals for steel-aluminum alloy or SiC-forged steel pairs.And the noise signals are generated from the unstable vibratory response due to friction-induced vibration corresponding to the fundamental frequency of the friction system.2.The magnetic field is able to attract the ferromagnetic wear debris of steel-forged steel,which can make the friction interface smoother,stabilize the friction system,and consequently reduce the vibration and noise.For steel-aluminum alloy and SiC-forged steel,the amount of the wear debris did not change significantly before or after the addition of magnetic field.Accordingly,the magnetic field could not distinctly reduce the amplitudes of unstable vibration or noise of these two friction pairs.3.Blowing air would not clean up the compacted wear debris thoroughly,instead the residual wear debris will cause the friction interface become irregularly,which deteriorate the friction-induced vibration and noise.Adding a magnetic field for the first time can remove the debris thoroughly,which make the wear trace very clean and the friction system stable.Adding a magnetic field for the second time cannot remove all of the wear debris.Some scattered upright wear debris will stay inside the wear trace because of the attraction of disc.The wear debris is able to avoid contacting with the steel ball specimen because of the repulsive force between the scattered upright wear debris,which cannot make the friction system produce unstable vibration and noise.4.Due to the attraction of disc,some wear debris will move from the wear trace to the edge of the disc.In addition,the wear debris diverges outward because of the existence of a repulsive force between the wear debris.