Measurement of burr removal rate and analysis of machining parameters in ultrasonic assisted dry EDM (US-EDM) for deburring drilled holes in CFRP composite

[Display omitted] •The novelty of a burr removal rate (BRR) model was proposed and validated in this study.•The influence of the US-EDM process parameters on the BRR value was studied.•The relationship between the input and output processes was evaluated statistically.•The optimal machining parameter for the BRR value was validated.•The comparison between US-EDM and Dry-EDM process was evaluated. An ultrasonic assisted dry electrical discharge machining (US-EDM) process in a gaseous fluid medium was proposed to remove the burrs formed on the exit region of a drilled hole. In preliminary experiment, three different electrode tools (copper, brass, and aluminum) were utilized. In secondary experiment, US-EDM and dry-EDM were compared and performed using the copper tool. US-EDM parameters, such as capacitance (C), pulse-on time (TON), and vibration amplitude (Ap-p) were considered as functions of the predicted burr removal rates (BRRs) model. Based on signal to noise (S/N) ratio analysis, machining parameters C=10−2µF, TON=150µs, and Ap-p=4.919µm provided the optimal BRR. The BRR was affected the most by capacitance, followed by pulse-on time and ultrasonic vibration amplitude. The copper tool provided a higher BRR than other tools. US-EDM is considerably effective when TON is low and the performance of US-EDM is better than that of Dry-EDM. Scanning electron microscopy (SEM) analysis showed that the US-EDM method created a heat-affected zone surrounding the machined surface of the deburred exit hole in range of 200µm–500µm.