Physico-Mechanical and Tribological Properties of Carbon-Containing Surface Nanocomposites Produced by Electrospark Alloying

Abstract

Nanostructured composite surface layers of metal articles improve the operating characteristics of the work-piece. Under the conditions of electrospark alloying (ESA), both the material transfer to the treated surface and the change in its characteristics under the influence of an electric discharge occur. A possibility of surface modification during ESA with the use of electrodes containing carbide phases, as well as with the use of graphite electrodes in order to form such phases, has been investigated. In this case, the main purpose was to strengthen the surface and to increase its friction resistance. The electrodes of T15K6 and VK8 alloys, as well as of steel 45, tungsten, and graphite, were used. It is shown that the presence of carbides in the surface layers has a decisive influence on the wear resistance, in particular, when a steel 45 electrode is used. With an increase in the carbides’ concentration in the substrate, the wear resistance of the obtained layers also increases. It is shown that the ESA treatment with tungsten and graphite electrodes with sequential deposition of a number of alternating layers allows the production of carbide-containing surface layers directly in the alloying process.