OBRABOTKAMETALLOV technology Vol. 26 No. 2 2024 Fig. 2. Appearance of a baking oven of JSC SHMZ Ta b l e 2 Coating parameters Powder name Flow rate of fuel mixture components (m3/h) Powder consumption (g/h) Spraying distance (mm) air oxygen propane (30 %) + butane (70 %) Fe2O3 1.41*/1.08** 2.87*/3.26** 0.54*/0.65** 11 40 Al2O3 + 10 % Fe2O3 1.41*/1.08** 2.87*/3.26** 0.54*/0.65** 52 70 Ti + 10 % Fe2O3 1.3*/1.54** 2.44*/3.04** 0.56*/0.67** 78 65 * – cylindrical combustion chamber; ** – annular combustion chamber/ contamination was removed from the surface of the metal plate by compressed air not worse than the 1st class of contamination according to GOST 17433. The modes of coating on the surface of the experimental specimens are given in Table 2. The coatingwas applied bymoving the barrel in the vertical scanningmodewith a transverse displacement of 5 mm in one pass. The inner diameter of the barrel was 16 mm, the barrel length was 500 mm, and the detonation frequency was 20 Hz. The barrel displacement in vertical scanning mode for Fe2O3, Al2O3 + + 10 % Fe2O3 and Ti + 10 % Fe2O3 composite coatings was carried out at a speed of 2,000 mm/min, 1,000 mm/min, 1,500 mm/min, respectively. To determine the microstructure and phase composition, the obtained experimental specimens were sawn into 4 parts with dimensions of 20×20 mm using an IsoMet 5000 precision cutting machine. The microstructure, elemental composition and morphology of the obtained coatings were investigated by scanning electron microscopy on a scanning electron microscope Mira 3 LMU (Tescan, Czech Republic). A reflected electron detector was used in high-resolution mode at an accelerating voltage of 15 kV to obtain images of the surface of composite coatings and areas for the study of the elemental composition. The elemental composition of the specimens was studied by energy dispersive spectroscopy (EDS) in the AZtec 3.1 microanalysis system using an X-Max 50 detector (Oxford Instruments NanoAnalysis, High Wycombe, England). The accumulation of EDS spectra and elemental composition distribution maps was carried out at an accelerating voltage of 15 kV, working distance 15 mm. The beam current was set so that the signal level was about 4,000–5,000 pulses per second.
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