Investigation of the Influence of Reduced Graphene Oxide Flakes in the Dielectric on Surface Characteristics and Material Removal Rate in EDM

Abstract

Electrical discharge machining (EDM) is an advanced technology used to manufacture difficult-to-cut conductive materials. However, the surface layer properties after EDM require additional finishing operations in many cases. Therefore, new methods implemented in EDM are being developed to improve surface characteristics and the material removal rate. This paper presents new research about improving the surface integrity of 55NiCrMoV7 tool steel by using reduced graphene oxide (RGO) flakes in the dielectric. The main goal of the research was to investigate the influence of RGO flakes in the dielectric on electrical discharge propagation and heat dissipation in the gap. The investigation of the influence of discharge current I and pulse time ton during EDM with RGO flakes in the dielectric was carried out using response surface methodology. Furthermore, the surface texture properties and metallographic structure after EDM with RGO in the dielectric and conventional EDM were investigated and described. The obtained results indicate that using RGO flakes in the dielectric leads to a decreased surface roughness and recast layer thickness with an increased material removal rate (MRR). The presence of RGO flakes in the dielectric reduced the breakdown voltage and allowed several discharges to occur during one pulse. The dispersion of the discharge caused a decrease in the energy delivered to the workpiece. In terms of the finishing EDM parameters, there was a 460% reduction in roughness Ra with a uniform distribution of the recast layer on the surface, and a slight increase in MRR (12%) was obtained.

The Accuracy of Finishing WEDM of Inconel 718 Turbine Disc Fir Tree Slots

“…The verification of the statistical significance was conducted by one-way analysis of variance ANOVA. The probability p was equal to p = 1.677 × 10 , which confirms the statistical significance of the model expressed by Formula (6). The graphic interpretation of the developed model is presented in Figures 7 and 8.…”

“…EDM is widely used in manufacturing injection molds and in the automotive industry [ 3 ]. The continuous development of this machining method and innovations in the design of EDM machine tools allow applying the method in the medical sector and aerospace industry as well [ 4 , 5 , 6 ]. Wire electrical discharge machining (WEDM) is a type of electrical discharge machining in which the tool is an electrode in the form of a wire.…”

Experimental INVESTIGATION OF influence WEDM PARAMETERS ON SURFACE ROUGHNESS AND FLATNESS DEVIATION

“…WEDM material is removed by a series of discharges occurring in the gap between the wire electrode and the workpiece. Electrical discharges cause melting and evaporation in local surface layers of both the workpiece and the working electrode [9][10][11][12]. The heat also causes evaporation of the dielectric liquid (deionized water) and induces high-pressure waves that wash the molten and/or vaporized metal.…”

Recent Advances and Perceptive Insights into Powder-Mixed Dielectric Fluid of EDM

“…Studies using graphenes are recent in this field. Different characteristics like erosion characteristics, surface characteristics, surface integrity, and machining parameters were studied using grapheme oxide [ 140 , 141 , 142 ].…”