DETERMINATION OF THE INFLUENCE OF THE MIXTURE OF GASES ON IMPROVING THE QUALITY OF CATHODES FOR ION-PLASMA SPUTTERING

Purpose. Improvement of the technological modes of smelting sputtering cathodes based on nickel of the Ni-Cr-Al-Y system in order to improve their quality, namely, to reduce the total number of defects in the form of discontinuities, pores, non-melts and increase the homogeneity of the structure and chemical composition and application of the protective atmosphere of inert gases, the most widespread of which are helium and argon. Research methods. The equipment was improved, in particular, the vacuum-arc installation was equipped with a ramp and a helium cylinder. Test samples in the form of “washers” (diameter 127 mm and thickness 40 mm) were obtained, which were used to study the microstructure and chemical composition. Remelting modes have been worked out. The study of the chemical composition was carried out using a multipurpose scanning electron microscope REM 106I, equipped with a microanalysis system. Results. Based on the results of studies of the influence of the gas mixture concentration on the structure and composition of the cathodes, technological modes of melting were established, which made it possible to improve the quality indicators and economic indicators of the investigated cathodes. This will have a positive effect on the number of cathode failures, the performance of coated parts and the life of aircraft engines in general. Scientific novelty. The dependence of the influence of the concentration of the mixture of gases (argon-helium) was determined, which made it possible to obtain the optimal ratio of protective gases. With a gas ratio of 70/30 %, the highest quality cathodes were obtained, which were used for further research. Practical value. Quality of coating sputtering is determined by regimes of sputtering and quality of cathode itself. One of applied methods is by-layered melting of cathodes in copper water-cooled crystallizer using electrodes that are melted or non-melted. Optimal ratio of protective gases for receiving qualitative cathodes is determined.