Application of additional voltage in electric spark processing

This article discusses the current problem of obtaining thick-layer electro spark coatings with small roughness, and presents studies of the effect of additionally introduced voltage in the natural air processing environment and in the protective gas environment of argon, on the modes operating of the SZ-8100 model electro spark installation. To increase the thickness of the resulting electro spark coatings, a method was used to introduce a higher voltage between the electrode and the product, and to study the effect of this voltage on the quality characteristics of the coating. The work carried out in 40 modes of electro spark build-up, the current frequency f it cheated in the range of 50...100 Hz, the duration of the current working cycle η cheated within 20...30 %, with a voltage on the electro spark installation of 100 V, additional voltage served through the rectifier VS-300B, increasing the voltage within 35...75 V. For electro spark build-up used, MP-3 (rutile) electrode and ERNiCr3 (nickel) electrode. Electro spark build-up carried out with argon and without argon. Installed, that the additionally introduced voltage not only increases the pulse energy, but also promotes inter electrode electro spark breakdown, electrode heating and facilitating the detachment of an electro-erosion metal particle. The influence of the supplementary voltage on the thickness and roughness of electro-spark coatings varies depending on the type of electrode markings: for example, using electrode MP3 and at raising the voltage to 75 V results in a 34 % increase in coating thickness and a 40 % rise in roughness, using a nickel electrode ERNiCr3 raising the voltage to 75 V, the corresponding increases are 16 and 43 %.Determined that the optimal values of additionally introduced voltage for the MP-3 electrode are in the range of 35—50 V. A comparative increase thickness when using an ERNiCr3 electrode in comparison with an MP-3 electrode, in identical "strong" processing modes, corresponds to increase in the thickness of the electro spark layer by 0.5 mm. Further study of the parameters of electro spark processing contributes to the development of methods for monitoring electro-erosion processes of electro spark build-up technology, which will improve the quality of electro spark coating formation.