INFLUENCE OF THE CURRENT AND ENVIRONMENT ON THE SUPERFICIAL STRUCTUREOF A GRAPHITE ELECTRICAL COLLECTOR

The mechanical effect of the sliding counterface leads to an orientati on of the superficial crystallites of a polycrystalline graphite colle ctor parallel to the sliding plane. The effect is favoured by the acti on of the environmental gases. When the contact is crossed by an elect rical current, the excellent mobility of the electrons between the bas al planes tends to reorient the superficial crystallites perpendicular to the sliding plane. The simultaneous effect of mechanical strain an d of the electrical current leads to a specific superficial morphology which can be observed by S.T.M.