The Study Of The Electrical Wear Properties Of CNTs-Ag-G Composites

In this paper, CNTs-Ag-G composite brushes are fabricated by means of powder metallurgy. Under no current and 10A/cm2 conditions, the friction coefficient, wear volume loss and contact drop of composites have been investigated and worn surface have been observed. The results show that the wear volume loss of electrical wear and the friction coefficient are more than that of mechanical wear. Because the current caused the high temperature of the brush, and the lubrication film was then destroyed. So the wear volume loss of electrical wear was more than that of the mechanical wear also because of the additional electric wear, and the friction coefficient was same to the wear volume loss. The effect of different brush pressures on the electrical wear properties of the composite brushes has been investigated. We can find that as the brush pressure increase, the volume loss of the composite is varied as "U". When the brush pressure is smaller or bigger, the lubrication film will be destroyed, and the friction coefficient will become bigger, so the volume loss of the composite will be bigger than the normal. The contact drop became smaller gradually as the brush pressures' decrease. We also found that the wear volume loss of positive brush is more than the loss of negative brush, because the positive brush is oxidized and made the positive brush wear out more rapidly. The friction coefficient under mechanical wear is larger than that under electrical wear, due to the forming of better lubrication film under mechanical wear.