Electrical discharge machining

Abstract: Abstract In this research, influences of cryogenically treated Inconel 718 work material in near-dry wire-cut electrical discharge machining (WEDM) characteristics have been studied using argon-mist (mixing of pressurized argon gas and minimum amount of tap-water) and a reusable Molybdenum wire tool. The effect of cutting parameters (pulse width (PW), spark current(C), pulse interval (PI), and flow rate(F)) on surface roughness (SR) and cutting rate (CR) and using Box-Behnken response surface analysis. It was observed that CR and SR are increased by increasing PW, and C; conversely, reduced by increasing PI. The technique for order of preference by similarity to ideal solution (TOPSIS) method has been utilized to estimate the best parameters’ settings for improving both machining characteristics. The optimum CR (9.81 mm 3 min) −1 and SR (1.9 μ m) have been obtained by optimum settings of 4 Ampere spark current, PW of 20 μ s, PI of 72 μ s, and 18 ml min −1 of the flow rate of mixing water using the TOPSIS method. The best settings of cutting parameters obtained from the TOPSIS method were considered to compare the near-dry WEDM performance using cryogenically treated/untreated work materials. It was observed that CR and SR of the cryogenically treated work material are 9.17% increased and 21.58% reduced than the untreated work material due to an increase in electrical and thermal conductivities.

Abstract: Surface texturing can be applied to improve tribological performance of mechanical contacts, in particular in the case of lubricated systems. The purpose of this work was to improve an alternative method for surface texturing based on electrochemical dissolution without previous masking of the workpiece named maskless electrochemical texturing (MECT). Electrochemical dissolution combines high speed, good reproducibility and high cost-benefit ratio, which are important factors when an industrial application of surface texturing is pursued. The use of electrical discharge machining (EDM) for the manufacturing of the MECT tools enabled different microtexture patterns to be produced. The cathodic tool was an AISI 430 ferritic stainless steel plate containing a pattern of microholes and covered with an insulating paint layer. The effect of important parameters such as the gap between electrodes, the applied voltage and the texturing time were evaluated. Different texturing patterns containing dots, trace-dots and chevrons were successfully obtained using a NaCl solution electrolyte. Tribological tests textured surfaces under starved liquid lubrication showed friction and wear reduction, when compared with a smooth surface.

Abstract: Micro-electrodischarge machining (EDM) can produce microhole and other complex three-dimensional features on a wide range of conductive engineering materials such as titanium super alloy, inconel, etc. The micromachining of titanium super alloy (Ti—6Al—4V) is in very high demand because of its various applications in aerospace, automotive, biomedical, and electronics industries, owing to its good strength-to-weight ratio and excellent corrosion-resistant properties. The present research study deals with the response surface methodology (RSM) and artificial neural network (ANN) with back-propagation-algorithm-based mathematical modelling. Furthermore, optimization of the machining characteristics of micro-EDM during the microhole machining operation on Ti—6Al—4V has been carried out. The matrix experiments have been designed based on rotatable central composite design. Peak-current (Ip), pulse-on time (Ton), and dielectric flushing pressure have been considered as process parameters during the micr...