Mechanism study of micro-electrical discharge drilling method during micro-dimpling

This paper reports the cutting mechanism in micro-electrical discharge drilling (uEDD) during a micro-dimpling process. A combination of fundamental micro-drilling and micro-electrical discharge machining (uEDM) is considered the main mechanism in the uEDD process. First, the cutting force in micro-drilling was modeled on a chisel and lip section based on a mechanistic model of the oblique cutting. Second, the model of the uEDM was also included based on uniform heat flux. Experiments of a micro-dimple were carried out on a titanium alloy (Ti6AI4V) to confirm the model validity. The validation confirms that the proposed cutting force model can be applied to predict the thrust force during micro-dimpling under uEDD. In addition, a micro-dimple morphology is also discussed.