Effect of Process Parameters on the Surface Integrity of Micro-Holes of TI6AL4V Obtained by Micro-EDM

This paper presents machining of the Ti6Al4V sheet using micro-EDM process. The influence of input parameters such as machining voltage and machining on time on the recast layer, micro-hardness, and change in chemical composition of the machined sample has been investigated. The recast material thickness was estimated from FESEM images corresponding to different pulse-on time duration and voltage with and without assisted vibration of the job. It is observed that by use of ultrasonic vibration to the job, the thickness of the recast layer is comparatively less. The changes in the micro-hardness of the machined workpiece were evaluated using a micro-hardness testing machine and found that the hardness of the fabricated micro-holes improves significantly on the introduction of ultrasonic vibration to the job. The change in element composition of the workpiece surface due to micro-EDM process was observed through EDS analysis. It was observed from the results of the EDS analysis that less amount of the residuals of the carbon and oxygen were present on the surface of the machined sample.