RESEARCH OF QUALITATIVE CHARACTERISTICS OF ELECTRO SPARK COATINGS OBTAINED DEPENDING ON THE CURRENT FREQUENCY AND CURRENT DUTY CYCLE

In modern automotive repair production, it is necessary to reintroduce electro spark processing of machine parts to address a range of challenges in mechanical engineering and repair. It is known that electro spark treatment of wear-resistant coatings is one of the resource-saving technologies for restoring and strengthening parts. This article examines the pressing issue of increasing the thickness of electro spark coatings and presents research on the influence of current frequency and duty cycle on the thickness of coatings produced by the SZ-8100 micro-welding apparatus. To enhance coating thickness, a method of electro spark treatment is proposed by identifying optimal parameters for the electro spark setup, such as current frequency and duty cycle. Specific results were obtained from studies on the effect of current parameters on coating thickness for St3 steel samples, where the following variables were adjusted within defined intervals: f – current frequency (Hz) and η– duty cycle (%). The experiments were conducted under 42 different modes, with current frequency f varying between 500–3000 Hz and duty cycle η ranging from 1–10%. The voltage remained constant at 150 V. The electrode used for deposition was a nickel alloy ERNiCr-3. The study yielded data on the relationship between the total coating thickness and the selected operating modes of the electro spark setup. The influence of current parameter variations on coating thickness was clearly demonstrated and graphically visualized using Microsoft Excel. The experimental results revealed that the greatest coating thicknesses were achieved at duty cycle of η = 10% and η = 6%, combined with current frequencies f = 2500 Hz and f = 3000 Hz, respectively. This research provides insights for selecting optimal parameters of electro spark , which will improve the productivity and quality of achieving the required thickness of electro spark coatings.