High speed short electric arc deep hole drilling experimental study based on tube electrode

Abstract

To improve the machining efficiency and dimensional accuracy of deep hole drilling, a novel and efficient method of short electric arc drilling (SEAD) by tube electrode is proposed. However, due to the mismatch between excessive arc discharge energy and feed rate, efficient and high dimensional accuracy deep hole machining is fraught with difficulties. This paper reveals the SEAD mechanism based on pulsed power supply, and analyzes the voltage-current waveform and cross-section topography. In addition, the effects of different electrode polarity, voltage, pulse frequency, duty cycle and electrode feed rate on the material removal rate (MRR), relative electrode wear ratio (REWR), average diameter, taper and thickness of the recast layer are also investigated. Finally, an optimum parameters combination was obtained through process parameters optimization experiments, which confirmed the SEAD machining performance. The experimental results show that the SEAD achieved the highest MRR of 369.02 µm/s and the machining time was only 121.91 s with the optimal process parameters. The average diameter of the machined deep hole was 1264.56 µm, the depth was 44.99 mm, and the depth-to-diameter ratio was 35.57.