A study on influence of peak current and ultrasonic vibration during powder mixed electrical discharge machining process

Abstract

Abstract This paper presents the influence of peak current and induced ultrasonic vibration into the dielectric medium during powder mixed electrical discharge machining (PMEDM) process. Molybdenum-di-sulphide powder of 90nm size is used as conductive particle mixed in hydrocarbon based dielectric medium during EDM process. Peak current is varied at 0.5A, 2A, 9A and 21A; parameters such as pulse duration 10μs, gap voltage 20V and duty factor 2 were maintained constant. Two set of experiments were conducted by varying peak current; one by induced ultrasonic vibration during PMEDM and another without ultrasonic vibration. The effect of peak current and ultrasonic vibration on material removal rate, surface roughness and crater diameter were analysed. Scanning electron microscope images and 2D roughness profile were used to analyse surface integrity. It is observed that the induced ultrasonic vibration improves MRR by 6 times, surface roughness (Ra) of 1.464 µm, small crater diameter and debris free surface is achieved.