The Development of Nanostructuring Method Metal Surfaces by Electrospark Alloying

The paper analyzes the works dedicated to solving surface nanostructuring methods. A method of obtaining nanostructured coatings by electrospark alloying (ESA) using special technological media (STM) created between the anode and the cathode (detail) and containing nanocrystalline particles in a dosed amount is proposed. The characteristics of the coating structure formation of Armco iron by the Mo electrode used of the STM with carbon nanotubes have been considered. The influence of the ESA regimes and the composition of the STM on the microstructure and hardness of the coatings has been studied. The microstructures after the ESA consist of zones: the “white” layer, the diffusion zone, and the substrate. In the microstructures, nanoscale phases of 40 to 60 nm are detected and are uniformly distributed in the coatings. The addition of Tuball Ocsial nanotubes (0.01 wt%) increases the hardness from 446 to 1438 HV. The coatings are formed with a uniform distribution of molybdenum. Carbon, apparently in the form of carbon nanotubes, is concentrated on the surfaces of the samples being processed. Their introduction into the STM helps to increase hardness and continuity. The addition of nanotubes has a positive effect on the quality of the coatings.