Accuracy improvement in nanographite powder-suspended dielectric fluid for micro-electrical discharge machining processes

Micro-electric discharge machining (μ-EDM) is an important manufacturing process that is able to produce components and tools with micro-features. Improvement to this process has resulted in the use of powder mixed dielectric (PMD), which results in better surface quality and faster machining time. However, the presence of conductive powder in the dielectric fluid negatively affects the accuracy of the machining depth. This paper presents a novel method of suspending nanographite powder in dielectric fluid, using ultrasonic vibration of dielectric fluid, and using the number of discharge pulses in order to improve the accuracy of the PMD-μ-EDM process. As a result, machining time has been significantly reduced up to 35%, accuracy increased, and the appearance of micro-cracks on the workpiece surface has been reduced.