Experimental research and multi-objective optimization of ultrasonic vibration–assisted EDM for Ti6Al4V micro-holes

Ultrasonic vibration–assisted electrical discharge machining (UEDM) was studied to improve the machining performance for TC4 micro-holes. First, a computational fluid dynamic (CFD) model of inter-electrode gap for the micro-hole was established using COMSOL Multiphysics, and the effect of ultrasonic amplitude on the distribution of fluid and debris in the inter-electrode gap was analyzed. The experimental study of UEDM for machining performance of TC4 micro-hole under different machining parameters was conducted by using the controlled variable method. Results showed that the ultrasonic vibration of the electrode is beneficial to improve the machining performance for micro-hole. Under the optimal processing parameters, the material removal rate is improved four times, and RTWR and θ are reduced by about 50%. Finally, the neural network and genetic algorithm were used to predict and optimize the experimental results. The average error is 4.1% between the optimal processing parameters [Xn] obtained by the above method and from the experiment.