Electrospark coatings produced by ceramic nanostructured SHS electrode materials

Abstract

The paper considers the possibility to expand the number of materials used for electrospark alloying. Ceramic nanostructured TiB₂–TiC–Al₂O₃–ZrO₂-based materials produced by means of SHS extrusion are used as electrodes. The regularities of the alloyed layer formation with electrospark alloying (ESA) are studied. Three different modes of anode erosion and cathode gain are observed for single pulse energies ranging from 0.05 to 2.5 J. The microstructure of the coatings is studied. It is shown that, in the case of ESA by ceramic SHS electrodes, nanosized crystallites are formed. The microhardness of the alloyed layer is 1250 HV. The tribological tests of the protective coatings demonstrate a high wear resistance (10^–5 mm³/N/m) and low friction coefficient (0.2).