Analysis of the oxide occurrence on WEDM surfaces in relation to subsequent surface treatments

Abstract

Surface treatments are typical surface protection against corrosion or serve to create an attractive appearance for the end customer. However, the surface to which they are applied must be completely oxide-free, otherwise, defects occur which can cause subsequent corrosion or deterioration of the visual appearance of the product. The parts manufactured by wire electrical discharge machining, however, have a high tendency to oxidize. For this reason, this study was aimed at demonstrating the effect of machine setup parameters (gap voltage, pulse on and off time, wire feed and discharge current) on oxygen occurrence on the surface of two non-metallic (aluminium alloy 7475-T7351, chromium nickel superalloy Inconel 625) and four metallic materials (tool alloy steel X210Cr12, Hadfield steel, Creusabro 4800 and Hardox 400). Within this study, 18 samples were produced, where the chemical composition of energy-dispersive X-ray was analysed, on the basis of which the effect of these parameters on the surface oxidation was proved.