OBRABOTKAMETALLOV technology Vol. 27 No. 1 2025 a b Fig. 5. Processing of sample sections at oscillating system inclination angles of: a – 75° and b – 45° When plotting the dependencies of the roughness parameters, the values were taken as the arithmetic mean of five measurements at different sections of the specimen. The obtained experimental data were approximated using the least squares method. Numerical and graphical processing of the measurement results was performed in the Statistica program. Since the spread of the obtained values did not exceed the 3σ interval, the data can be considered reliable. Assessment of the surface structure and properties The microstructure and microhardness of the control and processed specimens were also assessed. The microstructure was studied using a metallographic microscope METAM RV-22 (LOMO JSC, St. Petersburg, Russia), which is an inverted microscope with a top stage. The microscope is designed for visual observation of the microstructure of metals, alloys, and other opaque objects in reflected light under direct illumination in brightfield and darkfield modes. The magnification range is 80×–1,000×. The microhardness of the specimens was measured using a PMT-3 microhardness tester (LOMO JSC, St. Petersburg, Russia) according to the procedure based on GOST 2999–75. The depth of the modified layer was determined in a normal section. Assessment of friction and wear The obtained samples were subjected to friction and wear tests. The tests were performed using a universal friction machine MTU-01 (Prodvinutie Tekhnologii LLC, Moscow) [38] according to TU 32.99.53-001-78940767–2018. The tests were conducted without the use of lubricants on specimens representing a segment of the cylinder specimen. A cup made of steel 45 with an outer diameter of 34 mm and a wall thickness of 10 mm was used as the counterbody. The friction torque and axial load on the machine spindle were recorded using MTU-01 strain gauges. The contact scheme: the end of the rotating cup and the cylindrical surface of the specimen. Graphical representation of the changes in the registered parameters is recorded and processed by a computer using the software module QMbox. Wear during friction was determined by the change in weight of the tested specimens before and after the testing using analytical balance GF-1000 (A&D Company, Limited, Japan) with a sampling rate of 0.001 g. Results and Discussion Roughness The results presented in Fig. 6 were obtained under the selected ultrasonic surface deformation mode. In the presented graphs, the roughness values at α = 0° were obtained on specimens after turning with the selected mode but without ultrasonic exposure. The remaining dependencies were obtained during processing the specimens with tool inclination angles in the range of 45°–90°. A significant reduction in
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