Observation and modeling research of high-velocity flushing effect on the performance of BEAM

Abstract

Blasting erosion arc machining (BEAM) is a novel high efficiency electrical erosion process, which is characterized by a powerful multi-hole inner flushing. In order to study the influence of the high-velocity flushing on the performance of BEAM, a single discharge experiment is carried out on a specially designed observation apparatus, and the phenomena that occurred during the discharge is observed using a high-speed video camera. During the discharge process, a spray cloud of the removed debris near the downstream side of the discharging point is captured by the camera. Tail shaped crater and erosion-corrosion features are also found on the workpiece and electrode surfaces, respectively. These observed phenomena imply that the high-velocity flushing can greatly improve the melting metal removal from the molten pool thereby improving the material removal rate (MRR). For purpose of exploring the mechanism behind, the flow field and pressure distribution of the high-velocity flushing are analyzed by using computational fluid dynamic (CFD) method. The analyzed results indicate that a low-pressure suction effect exists on the downstream side of the electrodes. With the help of the low-pressure suction effect, the high-velocity flushing can continuously take the molten metal out of the molten pool during the discharge, resulting in the reduction of the overheating of the molten metal and improve the efficiency of Fawang Zhang the discharging energy. Thereby, the work in this paper helps to explain why the high-velocity flushing can markedly promote the material removal rate.

Experimental research on short electric arc milling machining based on the mechanical-fluid coupling effect

“…This is consistent with the main purpose of high-pressure flushing adopted by BEAM based on the hydrodynamic arc-breaking mechanism. 22…”

“…This is consistent with the main purpose of high-pressure flushing adopted by BEAM based on the hydrodynamic arcbreaking mechanism. 22 Figure 6(a) reveals that when the tubular electrode was rotated at a high speed and had high-pressure flushing fluid inside, the inter-pole voltage and current waveform broke and were relatively uniform. This indicates that the arc broke relatively uniformly during the process and proves that the mechanical-liquid coupling method was more effective in breaking the arc.…”

Effects of process parameters of fast EDM drilling on the recast layer

“…The increase in flow velocity in the gap flow field has a significant impact on the molten material in the molten pool and the debris detached from the molten material. Regarding the molten material in the molten pool, referring to the research of Zhang et al [22] and Zhu et al [23], increasing the flushing flow rate can effectively reduce the molten material in the molten pool, reduce the volume of molten material that ultimately solidifies into a recast layer, and reduce the generation of the recast layer from the molten material. For machining debris that detaches from the molten pool, the movement speed after entering the gap flow field is closely related to the flushing pressure.…”

The Use of Electrode Tools Obtained by Selective Laser Melting to Create Textured Surfaces

“…The performance of the EDM ET and the applicability of the ET produced by the selective laser melting method for EDM have not been fully studied [ 13 , 14 , 15 , 16 , 17 , 18 ]. The development of EDM technology by grown ETs obtained by the SLM method for applying a textured surface is relevant [ 19 , 20 ] ( Figure 2 ).…”