The present work is devoted to the study of the production of ultrafine-grained (UFG) spherical microparticles by electro discharge erosion (EDE) of the WC-15Co cemented carbide in glycerol, distilled water, and their solutions. Energy costs, productivity, particle size distribution, and morphological and chemical compositions of the obtained powders were studied. It was found that energy cost is reduced by 2.2 times when glycerol was used instead of water. The use of water reduces carbon content from 5.2% to 1.4%. The use of glycerol and its aqueous solutions reduces carbon loss and increases its content in the obtained powders from 3.2% to 6.1%. During SE, cobalt, carbon, and tungsten evaporate from spherical particles and crystallize in the form of ultrafine particles, which subsequently remain in suspension after sedimentation of spherical particles. Mass fractions of sedimented spherical particle fractions ranged from 75% to 82%. Cobalt and carbon content in the spherical particles obtained in glycerol decrease from 15% to 10% and from 5.2% t to 3.1% respectively. The particles consist of rounded carbide grains (β-WC and W2C) with a diameter of up to 500 nm, the space between which is filled with cobalt. Microhardness of the particles increased from 12.1 GPa (initial alloy) to 15.6 (EDE in water)—23.7 GPa (EDE in glycerol).

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The composite coatings Ti-Al, Ti-Al-Si-C and Ti-Al-B-C were formed on the Ti 6 Al 4 V titanium alloy by a new method of electro-spark deposition from granules. The granules were produced by sintering powders of titanium and aluminum mixed in a ratio of 3 :1, including 15 wt.% additives of silicon carbide and boron carbide. During coating, the frequency of the discharge pulses was 1 kHz, the on-pulse duration was 0.1 ms, and the deposition time was 12 min. The manufactured electro-spark coatings had a thickness of 20-40 µm. The composition of the surface layer formed by the deposition of pure intermetallic Ti 3 Al coincides with the composition of the initial material of the electrode. The Ti-Al-Si-C coatings are based on TiC, Ti 5 Si 3 and Ti 1+x Al 1-x. The electrospark coatings formed from Ti-Al-B-C granules contain intermetallic compound Ti 3 Al, borides TiB and TiB 2. Among the investigated samples, the Ti 3 Al +15%SiC coating has the highest microhardness, which is approximately 4 times higher than that of the titanium substrate from Ti 6 Al 4 V. The wear intensity of the titanium alloy during dry friction decreases by more than 19 times if it is coated with Ti 3 Al or Ti 3 Al +15%B 4 C coatings. The coating deposited from Ti 3 Al granules with 15 wt.% SiC additive has the highest wear resistance, its rate of deterioration is 38 times lower compared to Ti 6 Al 4 V. The friction coefficient of the obtained composite coatings is equal to 0.38-0.52. The oxidation rate of the titanium alloy during the isothermal heating at a temperature of 900°C can be reduced by 1.9 times if the alloy is coated with Ti 3 Al, and can be reduced by 2.3 times if the alloy is coated with Ti 3 Al with the additions of SiC or B 4 C.