Effects of processing parameters on processing performances of ultrasonic vibration-assisted micro-EDM

Abstract

To improve the processing efficiency and precision of micro-holes with a large depth-to-diameter ratio on titanium alloy, ultrasonic vibration-assisted micro-electrical discharge machining (micro-EDM) is adopted. It could improve the effective discharge ratio in the machining process and promote the removal of erosion products. Compared with the non-ultrasonic vibration-assisted micro-EDM machining of a large depth-to-diameter ratio on titanium alloy, when the ultrasonic amplitude was 6 μm, material removal rate (MRR) was increased by 2.4 times, relative tool wear rate (RTWR) was reduced by 65.8%, taper angle (θ) was reduced by 73%, and overcut (OC) was reduced by 32%. Based on the single factor experiment, this paper studied the influence rule and mechanism of processing parameters (pulse width, pulse interval, peak current, and ultrasonic amplitude) on the machining effect. Then, based on the orthogonal experiment, the optimization research on the processing technology of ultrasonic vibration-assisted micro-EDM was studied. The optimal processing parameter combination of MRR, RTWR, θ, and OC was obtained by signal-noise ratio (SNR) analysis. And regression analysis and analysis of variance were performed on the results, and the process models of ultrasonic vibration-assisted micro-EDM were established. The verification experiment proved the reliability of the single objective optimization result and the process model.