Study on the mechanism and key technique of ultrasonic vibration and magnetic field complex assisted WEDM-LS thick shape memory alloy workpiece

In this study, a novel complex technique of ultrasonic vibration (USV) and magnetic field (MF) assisted WEDM-LS (USV-MF complex assisted WEDM-LS) is proposed to enhance the machine characteristics and then to investigate the effects of the main process parameters on the MRR and surface quality including surface roughness (SR) in machining thick shape memory alloy TiNi-01. The principle and schematic diagram of the USV-MF complex assisted WEDM-LS machining setup are analyzed firstly. The vibration state simulation analysis of wire electrode in USV assisted WEDM-LS and USV-MF complex assisted WEDM-LS under different machining parameters were carried out in the paper. Then the simulation analysis of distribution of the discharge points on wire electrode in USV-MF complex assisted WEDM-LS shows the distributions of discharging points become more uniform reducing the broken electrode wire caused by the concentration of the discharge point of the electrode wire. The establishment of process parameters (MRR and Ra) models is finished and verified by experiments. Comparison of the experimental results of only MF assisted, USV-MF complex assisted and conventional WEDM-LS reveals that when process parameters are selected in the appropriate range, USV-MF complex assisted can significantly improve the ratio of normal pulse discharge states, increase the machining efficiency and improve surface quality simultaneously, reducing Ra. The proposed USV-MF complex assisted WEDM-LS process presents enormous advantages and potential for applications in the practical machining and manufacturing field.