Experimental Investigation on the Effects of the Geometry of Micro Hole on the EDM Drilling Process

In the last years, the interest in micromachining has grown significantly due to the miniaturization of several components used in several fields such as automotive, aerospace and bio-medical. In this scenario, the main protagonists are the microtechnologies and their capabilities. Micro EDM is a technology able to remove material from conductive workpieces through electrical sparks. Each spark makes a crater on the workpiece surface. Micro drilling is one of its common applications. In micro EDM drilling the geometrical characteristics of the hole are related to the electrode size. In this paper, the effects of the geometry of micro hole on the micro EDM drilling process performance have been investigated. In order to do this, experimental tests were conducted varying the electrode diameter and the aspect ratio of the hole. The influence of the electrode diameter and the aspect ratio on several indexes about process performance were established. This study contributes to improve the knowledge of the process and can support the users to establish the effects of the geometry of the hole on the machining performance.