OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 25 No. 4 2023 a b c Fig. 1. Kinetics of mass transfer during EDA with different pulse intensity: erosion of the anode ƩΔa, mg/cm2 (a); cathode weight gain ƩΔ c mg/cm2 (b); average mass-transfer coefficient ΣC t.a of specimens MS50, MS150, MS450 (c) X-ray diffraction analysis showed that in the anode composition of Fe31W10Cr22Mo7B12C18 contains phases of ferrochrome (Fe-Cr), borides and carbides: Fe23B4, MoFeB2, α-WC, Mo2C (fig. 2, a), which were not present in the composition of the powder mixture before melting. This indicates the intensive chemical reactions during the holding process of the composition presented in table 1 at 1,200 °C. Whereas on the X-ray spectra of coatings obtained with its use, no sharp Bregg reflexes are observed, and there is a wide halo in the range of angles 2Ѳ = 40–50°, indicating the amorphous structure of the deposited layers. Themain characteristics of EDA coatings on Steel 35 using Fe31W10Cr22Mo7B12C18 anode are summarized in table 3. The average thickness of the coatings was in the range of 56–80 μm, with a maximum at specimen MG50. The surface roughness of the coatings in terms of Ra parameter was in range of 6.79–5.46 μm with the increase in the duty ratio. The water contact angle ranged from 108.4° to 121.3° (fig. 2, b), which is higher compared to Steel 35 (57.5°). The free surface energy of the coatings was calculated and it was in the range of 29.9–32.3 mJ/m2, which is lower compared to the original base material (39.97 mJ/m2). This suggests that the application of Fe31W10Cr22Mo7B12C18 coatings can reduce the surface activity of Steel 35 to contaminants and corrosion [26]. a b Fig. 2. X-ray diffraction patterns of the anode of the Fe31W10Cr22Mo7B12C18 composition (a); wettability of the coating surface of the MG450 specimen (b)
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