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The present paper contains the results of some theoretical and experimental investigations on phenomena that take place at the interaction of electrical discharges in impulse with the surfaces of electrodes. Based on these results the author demonstrates the possibility of applying electrical discharges in impulse at modifying the microgeometry of piece surfaces, their cementing and microoxidation depending on the imposed conditions of functioning. An ample influence of different factors on the intensity of electroerosion process is analyzed in this work. The functional dependences of the electric as well as non-electric factors are established. The intensity of the process is an exponential function depending on the heat accumulation coefficient. The impulse duration is also influences the electroerosion character. It is underlined that short electric discharges are “anodic” and those of long duration are “cathodic”. Additional application on the gap of electric or magnetic field provokes amplification of electrodes’ erosion and stratum formation. The analyses of the results of experimental investigations on physico-chemical effects which are produced in the piece surfaces processed by applying electrical discharges in impulse (EDI) are made. It is stated that EDI cause micro-metallurgical phenomena, diffusion effects, chemical and structural modification of the machined surface composition and of its microgeometry. The graphite film formation provokes partial surface hardening simultaneously serving as ointment in solid state, the result being the increase of machined piece functional performances. All this contributes to increasing the hardness of the active surface and the absorption properties of different types of radiation.

The paper deals with the conditions for extraction and freezing of asperities in the form of Taylor cones from the metallic surfaces under the action of pulsed electric discharge machining. It is demonstrated that due to the presence of strong electric fields (greater than 108 V/m) generated by the presence of anode and cathode spots and under the simultaneous action of weight forces, as well as those of surface tension on the surface of the liquid metal, it develops disturbances and propagates capillary waves. As a result, conical asperities are extracted from the surface, with the top angle of 900. In the case of sudden cooling, these can be frozen in this state. A singular or multiple asperities simultaneous in the shape of Taylor cones can be obtained by solitary electrical discharges under certain energy and time conditions.

The paper presents the results of experimental research on the possibilities of micro-geometry modification of conductible and semiconductor surfaces, that gives them new functional properties. It emphasizes that surface micro-geometry modification occurs in practically all cases of the action by concentrated sources of energy, but a prescribed geometry can be reached only under strict conditions. The process of this geometry formation is a function of the physical and mechanical properties and the chemical composition of the processed material, the gradient of applied energy, the intensity of electric field applied in the interstice between the workpiece and the tool-electrode, the connection mode of the workpiece (as anode or as cathode) in the discharge circuit of the current impulse generator, etc. It highlights the fact that on the processed surface can be formed spherical shaped craters, round asperities or Taylor cone shaped asperities. Depending on the shape and the size of asperities, the active surface area, and, respectfully, the emission and absorption properties of elementary particles and light radiation are modified.

The experimental results aimed at modification of metal surface micro geometry by applying electric discharges in impulse are presented in this paper. Taylor cone-shaped asperities were extracted from the metal piece on the flat and cylindrical surface. SEM and EDX analysis of the processed surfaces were investigated

The paper presents the results of experimental research on the wear mechanism of the tool-electrode as a result of machining metal materials by applying electric discharges in pulse. It examines several phenomena noticed on the tool - electrode surface, exactly, the oxide layer formation and the modification of the micro geometry of the tungsten tool electrode surface. The paper presents the experimental results on the behavior of the tool electrode made of stainless steel after the metal parts have been machined. It also presents the phases of mass transfer in the gap between electrodes.

This paper presents the results of experimental research on Taylor cone shaped menisci formation on the surfaces of pieces by applying electric discharges in pulse. It examines the influence of energy stored in the capacitor and of pulse duration on their formation. The modification of piece surface micro-geometry aims to increase the capacity of absorption of radiation and of particle emission. It shows that the size of formed menisci depends on the energy regime of machining, on the gap size, on the duration of electric discharges in pulse and on thermal physical properties of the material used to execute the piece.