Influence of normal load, electric current and sliding speed on tribological performance of electrical contact interface

The purpose of this study is to investigate the effect of normal load, electric current and sliding speed on tribological performance of electrical contact interface. Sliding electrical contact tests of H65 material are carried out by using a customized ball-on-flat tribometer. Results show that with the increase of normal load, both the friction coefficient and contact voltage drop show a downward trend. Too low or too high load will not cause the generation of friction-induce vibration (FIV). Although increasing the normal load appropriately can improve the wear behavior of the interface, it will intensify wear if the normal load is overly high. Larger electric current will increase the friction coefficient, contact voltage drop and surface temperature, but reduce the contact resistance. A certain value of electric current will cause the generation of FIV. Larger electric current will destroy the surface lubricating film of interface and intensify wear. With the increase of sliding speed, the friction coefficient firstly increases and then decreases, while the contact voltage drop shows the opposite trend. Strong FIV will be generated at a certain value of sliding speed. Larger sliding speed will cause the formation of a dense film layer, which plays a good lubrication effect.