Fundamental Research on the Structure and Properties of Electroerosion-Resistant Coatings on Copper

The electroerosion-resistant coatings of CuO–Ag and ZnO–Ag systems were obtained on the Cu surface. Formation of coating was caused by the processing of copper surface with plasma formed in electrical explosion of silver foil with weighed sample of copper oxide or zinc oxide. After electroexplosion spraying, the electron-beam treatment of coatings was performed. The nanohardness, Young modulus, wear resistance, friction coefficient, and electrical erosion resistance of the formed coatings were studied. All studied properties exceed those of copper. Electrical erosion coatings were studied by the methods of scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. It became possible to achieve the high level of operational properties of electrical erosion coatings due to their nanostructurization. Structure of coating is formed by cells of high-speed crystallization. The size of cells varies within the range from 150 nm to 400 nm. The cells are separated by interlayers of the second phase whose thickness varies as 15–50 nm. By method of atomic force microscopy, the separate particles of ZnO or CuO of different shapes and 10–15 nm in size chaotically located in silver matrix were revealed as well as spherical particles of ZnO or CuO in size of 2–5 nm. The total thickness of coatings is 60 μm. The complex of studies we have carried out permits to recommend the integrated processing for strengthening the switch copper contacts of powerful electrical networks.