Study On The Interaction Between The Worn Surface Morphology And Arc In The Process Of Current-carrying Friction And Wear

In the process of current-carrying friction and wear,the morphology of the friction interface changes continuously,which will affect the arc discharge,and conversely the arc will affect the surface morphology.In order to study the dynamic change of the arc behavior and friction and wear performance,the exploration of the relationship between them is needed.To this end,the tests were carried out on HST-100 high speed friction and wear testing machine with copper / chromium bronze as friction pairs.The relationship between arc and the performance of current-carrying friction and wear were analyzed,combing the variation of friction coefficient and wear rate.Using scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS)for microscopic observation on the friction surface and longitudinal section,analyze characteristics of worn surface.The 3D surface topography explorer was used to measure the roughness of wear surface,and then the relationship between surface roughness and arc rate was analyzed.Based on the variation of wear rate and fric tion coefficient,the wear behavior of friction surface in the process of friction and wear was investigated,as well as the change of arc and its effect on the current and the properties of friction and wear.The results show that in the process of current-carrying friction,the friction surface has significant adhesive wear,and lamellar debris and rod-like debris are formatted.The worn surface and subsurface have a plastic deformation zone and the morphology of the zone varies with the distance from int erface.The plastic deformation zones have different sizes under different wear time.The plastic deformation zone is narrow and the stratification is not obvious when the wear time is short.With the increase of wear time,the plastic deformation zone becomes large and the stratification is obvious.In the later stage of wear,fused deposition is serious and severe plastic deformation layer is thick.The deformation of the whole area is reduced.For fine copper materials,arc erosion is mainly composed of melt splashing and fused deposition.In the process of current-carrying friction,the friction surface of fine copper is oxidized.The surface roughness varies with the arc parameters,the current-carrying capacity and the properties of friction and wear during the process of current-carrying friction and wear.The wear rate of the material shows a type of "U" curve,and the wear rate of the material is nonlinear proportional to the intensity of the arc.The init ial stage of wear has a high surface roughness and arc rate,and the corresponding arc energy is rather high as well as the wear rate.In the medium term,the surface roughness is low,while the arc frequency and the arc energy are small.The friction coefficient and wear rate are low,so the contact state of friction pair is better and the overall performance of current-carrying friction and wear is good.In the later stage of wear,the surface become more rougher,so the friction coefficient increases.With the arc energy and the wear rate increasing,the friction state is deteriorating.