A Wear Investigation of Repeatedly Used Wire in Wire Cut Electrical Discharge Machine
Wire electro-discharge machining (WEDM) is a fully extended and competitive machining process widely used for hard and difficult to machine materials. In the present research, experimental investigation have been conducted to find out the wire wear rate at different machining parameter Such as peak current, pulse on time, pulse off time, based on full factorial design of experiment. Molybdenum wire of 0.18 mm and EN-8 material were used as tool and work piece material for the experiment, ANOVA analysis were done to find out the effect of peak current, pulse on time, pulse off time on wire wear and found that the increasing in peak current slowly increase the wire wear but increasing in pulse on time increase the wire wear rapidly and pulse off time not much affects the wire wear. Keywords— WEDM, WWR, ANOVA, Full factorial,
Experimental investigation and prediction of optimum process parameters of micro-wire-cut EDM of 2205 DSS
Micro-wire-cut electrode discharge machining (EDM) is an emerging manufacturing process in the field of micro-manufacturing to fabricate the complex profiles of micro-components. It is a complex process involving various process parameters such as pulse on time, pulse off time, wire speed, wire tension and current. In addition to micro-fabrication, this process can also be extended in the field of tool design and developments such as dies, moulds, precision manufacturing, contour cutting, etc., where complex shapes need to be generated with high-grade dimensional accuracy and surface finish. In this research work, an attempt is made to investigate the effect of process parameters on the output variables such as material removal rate (MRR), surface finish and the cutting width (kerf) of wire-cut EDM for duplex stainless steel (DSS). Scanning electron microscopy (SEM) has been used to capture the images of the kerf width, and the measurements are taken with the help of the welding expert system and software. An optimization technique (Taguchi method) has been employed to identify the optimum parameters of the micro-wire-cut EDM process for cutting 2205 grade duplex stainless steel. The effect of each control parameter on the performance measure is studied individually using the plots of signal to noise ratio.
Adaptive control of the WEDM process using the fuzzy control strategy
Abstract The proportion of abnormal sparks (abnormal ratio) and the sparking frequency are employed to monitor and evaluate the gap condition of the wire electrical discharge machining (WEDM) process on-line. The relationships are investigated between these two sensing parameters and wire breaking phenomenon, metal removal rate (MRR), and surface roughness of the machined part under various machining conditions. Based on the results, an adaptive control optimization (ACO) system is developed. Fuzzy rules based on operator experience and expert knowledge are constructed, and a multivariable and three-region fuzzy controller is designed and implemented. By regulating the servo feed and the pulse off-time in real time, the abnormal ratio is controlled at a predetermined value for optimum and stable machining, while at the same time the sparking frequency is kept under a critical value for wire rupture prevention. Experimental results demonstrate that the developed control system results in very satisfactory performance.