DefinePK

Abstract

The presented study discusses the issues of wire-cut electrical discharge machining of small-sized products of complicated configuration made from tungsten. The wide-spread use of tungsten and its alloys is related to the fact that it satisfies the requirements for parts operating under extremely high temperatures. The part Slot mask was chosen as an experimental specimen. The technological application of this part is the measurement of the distribution of power along a section of an electron beam, which is used in electron-beam machining of materials. The aim of the presented study is the analysis of the influence of regimes of electrical discharge machining on the process of machining of small-sized products made from tungsten. In order to achieve the set goal, the mathematical and experimental study of electrical discharge machining was carried out. During the mathematical simulation, the spark gap value was taken into account. The experimental study was carried out using the wire-cut electrical discharge machine tool Electronica Eco Cut with various cutting regimes. The brass wire with a diameter of 0.25 mm was chosen as an electrode-tool during the experiment. The working media is distilled water. During the modeling, we considered the nature of the process of electrical discharge machining, which is the transformation of the electric energy of a sparkle charge taking place between the electrode-part and the electrode-tool, into thermal energy, which destroys part of the material. The obtained mathematical model was confirmed by the experimental results. In the study, it was established that the increasing power in the spark gap leads to an increase in the intensity of the removal of material, and, therefore, an increase in the speed of cutting. In the cutting zone there was intense evaporation and melting of metal under the action of non-stationary heat flux coming from heat sources, which have small sizes and small action time and which appear on electrodes under pulse charge. In the study, it was demonstrated that a decrease in the speed of cutting leads to the concentration of large thermal energy on a machined part and an increasing possibility of secondary spark charges, and, thus, increasing cut width. It was established that due to a higher speed it is possible to make thinner cuts. The technological regimes, which allow providing the designated precision parameters during production of the part Slot mask, were established.