Phase Composition and Morphology of a CuSn10Pb10 Bronze Surface after Electric Spark Machining Using Analogous Anodes

Scanning electron microscopy and X-ray diffractometry are used to study the coating layer deposited on a CuSn10Pb10 bronze surface through electric spark machining with anode material having similar composition. X-ray studies of the phase composition indicate the presence of copper–tin phases (Cu, α-(Cu; Sn), Cu3Sn, ε-Cu3Sn, and Cu5,6Sn) and lead. The ratio of intensities of diffraction maxima illustrates the absence of a predominant growth (texture) orientation in the coating obtained through electric spark deposition. Scanning electron microscopy data prove that the surface coating layer contains melted areas, pores, spherical and oval inclusions, irregularly shaped particles, cracks, rounded pits, etc. The main reason behind melted areas deals with high temperatures developing between electrodes during an electric spark discharge. The appearance of surface fractures can be primarily associated with developing high thermal stresses and mechanical contacts between electrodes. Spherical/oval particles can develop due to interaction of liquid droplets with the cathode substrate surface. Irregularly shaped particles appear as a result of explosive emission from the edges of the erosion crater of the anode material.