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In this work, coatings of composite carbide materials applied via electrospark deposition (ESD) with a low pulse energy on the most widely used titanium alloy Ti6Al4V and on a commercially pure titanium Ti-GR2 were obtained and studied. Dense coatings with sparse micropores and roughness Ra 2–5 μm, thickness 10–25 μm, and microhardness up to 3–4 times higher than those of the substrate were obtained. The influence of the electrode materials and the energy parameters of the ESD process on the roughness, thickness, microhardness, composition, and structure of the coatings and on their wear resistance were studied. A comparative analysis of the qualitative characteristics, composition, structure, and properties of the obtained coatings was made. The results of comparative studies at dry friction show that coatings from the TiCN-based composite electrodes, of the multicomponent ones based on WC, TiB2, and B4C, and from the electrodes based on TiB2 with nanostructured additives can achieve up to a threefold increase in the wear resistance of layered surfaces. Based on the results obtained, suitable materials for electrodes and parameters of the modes for their deposition were indicated. [ABSTRACT FROM AUTHOR]

This paper discusses the essence and technological characteristics of the process of electrospark deposition (ESD), its advantages and disadvantages with a view to its application for improving the tribological properties of titanium and its alloys. A summary of the available data and results in the literature devoted on the ESD of titanium and its alloys has been made. Based on the published data, a comparative analysis of the technical parameters and technological capabilities of the most common equipment, including contactless ESD, is presented. The geometrical and physico-mechanical characteristics of the coatings obtained with different equipment and the nature of their change depending on the technological parameters of the ESD mode and the type of the anode and cathode materials are shown. A summary of the data on the wear resistance of the coatings obtained with different electrode materials and modes are given. It has been demonstrated that ESD can be successfully applied to improve the wear resistance of titanium surfaces. Suitable electrode materials and process parameters for ESD on titanium alloys are indicated. [ABSTRACT FROM AUTHOR]

Results of the roughness studies of multicomponent hard metal layers on X12 tool steel (210Cr12/1.8–2.2% C, 12%Cr) obtained by contactless local electrospark deposition using two types hard metal electrodes (WC–TaC–Co–Al2O3 and WC–(Ti, Ta, Nb)C–Co–Al2O3) are presented here. Dense, smooth, and uniform coatings with a good repeatability of properties have been obtained. The minimal and maximal values of thickness δ, of the roughness parameter Ra, and of micro hardness HV of obtained coatings are changed by altering the stratification regimes in borders: δ = 3–12 μm, Ra = 0.8–2.2 μm and HV = 8.5–18 GPa, respectively. The influence of the process parameters and the electrode composition on the roughness of the layers obtained have been studied. Mathematical-statistical models and equations describing the roughness of the coatings have been created and worked out. They enable obtaining of coatings with a predetermined roughness by controlling regime parameters. Specific ways of obtaining coatings with reduced roughness at the maximum possible thickness, as well as recommendations for their appropriate application, have also been proposed and justified. Based on the obtained regression equations and graphical dependencies, it is possible to optimize properties of the coatings and the conditions of their deposition in order to obtain maximum tribo-effect and increased performance properties of the coated surfaces for different cases of exploitation. [ABSTRACT FROM AUTHOR]