The structural-phase state and durometric characteristics of hypersonic metallization coatings made of pseudoalloy "Fe-Al" in the initial state and after heat treatment were investigated. The heat treatment consisted in heating the coating samples to temperatures of 570, 620, 720, 820 and 920°C followed by holding for 5, 10 and 20 minutes and air cooling. The phase composition of the "Fe-Al" coating sprayed by hypersonic metallization in the initial state includes α-Fe, Al, Al 2 O 3 and FeO. The hardness of the coating is 220 HV10, and the microhardness of the steel interlayers is 350 HV0.025. It is shown that heat treatment of the coating in the temperature range 570 -920°С and holding time of 5 -20 minutes leads to the formation of strengthening intermetallic phases Al 5 Fe 2 , Al 13 Fe 4 , Fe 3 Al and FeAl in it. It is shown that the formation of intermetallic compounds in coatings leads to an increase in the microhardness of steel interlayers by up to 1.7 times as compared to the initial state, while an increase in exposure from 5 to 20 minutes at one temperature is accompanied by the formation of a large amount of intermetallic compounds with a high iron content Fe 3 Al and FeAl. It was found that an increase in the content of aluminum oxide and the formation of iron oxides are recorded under all heat treatment modes. Changes in the macrostructure of the coatings are recorded: as a result of low-temperature annealing at 570 -620°C, there is a significant increase in the porosity of the coatings up to 15 -25 vol.%. An increase in the annealing temperature to 720, 820, and 920°С is accompanied by a sequential decrease in the porosity of the coating to 15 -20, 7 -10, 6 -8 vol.%, respectively.

Comparative study of the structural-phase state and tribotechnical properties of gas-thermal coatings from steels 08Mn2Si, 40Cr13, 95Cr18, as well as the pseudoalloys 08Mn2Si + bronze SiMn3-1, 08Mn2Si + AlSi12, 40Cr13 + bronze SiMn3-1, 95Cr18 + brass 63Cu, 95Cr18 + Al99.9 is carried out. It is shown that gas-thermal coating made of 95Cr18 steel has the highest wear resistance under conditions of dry friction due to the occurrence of intense martensitic γ → α transformation in its surface layers during friction. It is established that the pseudoalloys 08Mn2Si + bronze SiMn3-1 and 08Mn2Si + AlSi12 have higher wear resistance compared to the coating made of 08Mn2Si steel, which is associated with low content of iron oxides in the coatings of falsely alloys. For coatings from pseudoalloys 95Cr18 + brass 63Cu and 95Cr18 + Al99.9 lower wear resistance is characteristic in comparison with coating of 95Cr18 steel. The reduced wear resistance of pseudoalloys based on 95Cr18 steel is associated with their relatively low strength characteristics compared to steel coating of wire tool steel.

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Исследовано структурно-фазовое состояние газотермических покрытий, напыленных на подложку из стали 20 методом гиперзвуковой металлизации из титанового сплава ОТ4. Определены размеры распыляемых частиц, фазовый состав покрытий, их твердость и микротвердость по Виккерсу. Рассчитана объемная доля нитрида титана на поверхности частицы. Установлено, что в результате гиперзвуковой металлизации на подложке формируется покрытие с высокой микротвердостью (1200 – 1600 HV0,025 ), содержащее до 55 % (об.) TiN. Рассчитан коэффициент диффузии азота воздуха в жидкие титановые частицы; температура протекания реакции — » 3100 – 3200 К. Сделано заключение, что образование нитридной фазы на поверхности жидких капель титана происходит за счет его взаимодействия с ионами азота воздуха при температурах выше 3000 К.