Energy of the Surface Layer Deterioration of 1020 Steel and Copper at Dry Sliding against 1045 Steel with a High Electric Current Density

Dry sliding of copper and 1020 steel against 1045 steel under the influence of the contact current density higher than 250 A/cm(2) is carried out by using the pin-on-ring testing scheme. The change in the surface layer structure and the formation of a tribolayer consisting of iron, copper, and FeO oxide are shown. It is noted that the thin contact layer contains near 40 at % of oxygen. The specific wear rate is calculated based on the data of wear and current-voltage characteristics of the contact. A limited applicability of this parameter for the description of the surface layer deterioration is shown. We propose a wear parameter close to it, which characterizes more correctly the specimen tribolayer deterioration. These wear characteristics increase with a current density increase. It is established that the work of tribolayer deterioration can be close to a half of energy generated in contact. Some increase in the work of tribolayer deterioration due to a reduction in heat flow to the specimen is noted. It is shown that these wear characteristics of copper are considerably lower than that of 1020 steel. It is explained by the presence of copper in the tribolayer of the copper specimen that allows an easier stress relaxation to be realized.