OBRABOTKAMETALLOV technology Vol. 27 No. 2 2025 a b Fig. 1. Images showing the condition of the samples side surface: a – top view; b – cross-sectional micrographic image treatment (1 hour), only a small number of loosely adhered powder particles were removed from the surface, with a negligible effect on the overall surface condition. Therefore, the surface was pre-treated in an etching solution consisting of hydrofluoric and nitric acids, as well as distilled water (3% HF + 5% HNO3 + H2O), according to the schemes shown in Fig. 2. To assess the effectiveness of ultrasound exposure, chemical treatment (CT) was performed in an etching solution without ultrasonic vibrations (Fig. 2, a). CT was performed by immersing the sample in the etching solution for 30 minutes. Every 10 minutes, the sample was removed, rinsed under running water for 1 minute, dried, and wiped with ethyl alcohol. The side surface was then photographed using a microscope. Fig. 2. Schematic diagrams of treatment The combined processes of CET + CT and CAT + CT were carried out by introducing an emitter of the ultrasonic rod oscillatory system PMS 2.0/22, consisting of a magnetostrictive transducer, which is a package of O-shaped plates made of permendur, and a titanium alloy waveguide soldered to it. The radiator made from VT-3 has a radiating surface diameter of 30 mm. The distance between the end of the radiator and the treated surface of the sample was 20 mm. The oscillatory system was powered by a UZG 2.0/22 ultrasonic generator. The resonant oscillation frequency was f = 19,750 Hz, the oscillation amplitude ξm = 20 µm. Under these treatment conditions, the power consumption of the generator was approximately 600 W. The oscillation amplitude of 20 µm corresponds to high-amplitude treatment conditions, where, in addition to cavitation bubbles, large-scale acoustic currents directed from the end of the radiator to the sample surface make a significant contribution to the treatment. Under the selected experimental conditions, the flow force of the formed streams exceeds the abrasive particles’ gravitational force, ensuring
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