FORMATION OF SURFACE PROFILE IN CONTROLLED PULSE MODES OF ELECTROLYTIC-PLASMA TREATMENT

To improve the efficiency of electrolytic-plasma treatment methods, modes based on the use of controlled pulses have been developed. The modes are implemented by alternating high-voltage pulses corresponding to the electrolytic-plasma region and current-free pauses between them. At the initial moment of switching on the high-voltage pulse, the electrochemical mode is in effect (at the stage of forming the vapor-gas shell). The efficiency of the pulse process is increased by intensive metal removal during the electrochemical mode and optimization of the duration of the electrolytic-plasma mode, which ensures high surface quality. According to the research results, it has been established that the developed pulse method, due to combining the advantages of both the electrolytic-plasma and electrochemical modes, ensures the formation of a surface with a smoother and flatter profile of microroughnesses compared to traditional electrolytic-plasma treatment with direct current. The presence of the electrochemical component leads to the preferential dissolution of high protrusions and intensive smoothing of irregularities, which helps to reduce the profile inclination angle and reduce the number of protrusions per unit length (HSC parameter). The accentuated dissolution of protrusions in the pulse process compared to direct current processing is confirmed by the dynamics of the change in the Rsk parameter, which determines the profile asymmetry (predominance of protrusions or depressions) — for the pulse mode, the Rsk parameter has higher values, which indicates a more intensive smoothing of protrusions.