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,
Monitoring and self-learning fuzzy control for wire rupture prevention in wire electrical discharge machining
Wire breaking is a serious problem in the application of wire electrical discharge machining (WEDM). A WEDM sparking frequency monitoring and control system based on the characteristics of the voltage waveform of WEDM is developed. A new self-learning fuzzy controller is proposed to control the sparking frequency at a safe level by regulating the pulse off-time in real time for avoiding wire rupture and maintaining a state of high metal removal rate. The developed control strategy is tested under the conditions of cutting a workpiece with continuous sharp angles, a change in workpiece height during machining process, and machining with a high feed-rate. Experimental results show that this monitoring and control system can control the sparking frequency at a predetermined level without the risk of wire rupture.
Anode Erosion in Wire-EDM – A Theoretical Model
Summary Theoretical predictions concerning the machinability of different materials by EDM are difficult because numerous aspects govern this problem. The influence of the thermophysical material properties which play a dominant role can be studied best by a theoretical model. Thus, a new model which is tailored after a typical wire-EDM discharge has been developed and experimentally verified. The model describes the impact of a discharge on the anode as a heat source on a semi-infinite solid whose size and intensity are time-dependent. The numerical analysis of this mathematical problem has been performed by using the Finite element method.