Фазовый состав и морфология поверхности бронзы БрО10С10 после ее электроискровой обработки анодным материалом аналогичного состава

Abstract

The coating on the surface of BrO10C10 bronze was studied by scanning electron microscopy and X-ray diffractometry. It was obtained by electrospark processing with an anode material with a composition similar to that of the substrate. X-ray studies of the phase composition revealed the presence of phases of the “copper – tin” system (Cu, α-(Cu; Sn), Cu3Sn, ε-Cu3Sn and Cu5.6Sn) and lead. The incorporation of atmospheric elements and initial bronze components into lead leads to the formation of regions with a distorted crystal lattice. An increase in the energy of a single pulse of an electric spark discharge is accompanied by a decrease in the α-(Cu; Sn) phase and an increase in the content of ε-Cu3Sn and Cu5.6Sn. The ratio of intensities indicates the absence of a predominant orientation of growth (texture) in the electrospark coating. Scanning electron microscopy data indicate the presence of melted areas, pores, spherical and oval inclusions, irregularly shaped particles, cracks, rounded pits, etc. in the surface layer. The main reason for the presence of melted areas is high temperatures in the interelectrode region during an electric spark discharge. The appearance of surface cracks is primarily associated with the occurrence of high thermal stresses and interelectrode mechanical contact. The presence of spherical/oval particles is a consequence of the interaction of liquid droplets with the surface of the cathode substrate. Irregularly shaped particles appear as a result of explosive emission from the edges of the erosion crater of the anode material.