Structure of Combined Intermetallic Electrospark Coatings on Steel 45

Abstract

The microstructure, phase composition and distribution of chemical components in two-layer coatings obtained by the method electrospark deposition (ESD) on steel 45 (cathode) are studied. It is shown that the lower layer formed by Ni or Cu acts as a damper preventing penetration of microcracks into the cathode from the upper layers of the coatings obtained from alloys based on the Ni – Al system. The two-layer coatings in all the cases have a gradient structure constituted by columnar crystallites, the concentration of components in which varies gradually over the thickness.