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The aim of the present work is to identify and formulate the basic principles and approaches for the selection of materials for electrical spark and gas-flame stratification of structural steels. For this purpose, have been examined: -The characteristic features and physical foundations of the two methods, the changes in the composition and structure of the coating materials in the transfer process and in the formation of the coatings and the general similarities and differences.-The regularities of formation and qualitative characteristics and properties of the coatings obtained, depending on the process parameters of the coating mode and the layering material.-The interrelation between: the process parameters of the application system; the coating material; the quality characteristics, the composition, the structure of the coatings; the mechanical and the tribological properties of the coatings. The requirements for coatings have been formulated for various loads and wear cases and on this basis the requirements for the layering materials are determined by the two methods. Appropriate materials and compositions are specified for various cases of friction and wear. The main approaches to the selection of the layering materials are described.

In the present work, abrasive and erosive wear of wear-resistant composite coatings with a complex structure and different phase compositions deposited on titanium surfaces was studied. The coatings were obtained by electrospark deposition (ESD) using two types of hard-alloy compositions: WC–TiB2–B4C–Co–Ni–Cr–Si–B and TiB2–TiAl reinforced with dispersed nanoparticles of ZrO2 and NbC. The influence of the ESD process parameters on the roughness, thickness, composition, structure and coefficient of friction of the coated surfaces was investigated, and their role in protecting the titanium surfaces from wear was clarified. Dense coatings with the presence of newly formed wear-resistant phases and crystalline-amorphous structures were obtained, with roughness, thickness and microhardness that can be varied by the ESD modes in the range Ra = 2.5 ÷ 4.5 µm, δ = 8 ÷ 30 µm and HV 8.5 ÷ 14.0 GPa. The new coatings were found to reduce the abrasive and erosive wear of the coated surfaces by up to four times. The influence of the geometric characteristics, composition and structure of coatings on the wear intensity and wear resistance of coatings was studied.

In this work contactless local electro spark deposition (LESD), has been used to received wear resistant coatings from hard alloys based of ТiC, TiN, TiCN onto high speed steel HS6-5-2. The influence of the operating electric parameters and the electrode materials on the roughness, thickness, microhardness, phase composition, and on the structure of resulting coatings was studied. The impact of different electrode materials on the quality characteristics, the composition and structure of the resulting coatings has been found. The technological parameters of the LESD process for the formation of coatings with a predefined roughness, thickness, composition and structure has been determined.