Observation and simulation investigation for the crater formation under discharge plasma movement in RT-WEDM

Autor: Xue-Cheng Xi, Zi-Lun Li, Qiang Gao, Ya-Ou Zhang, Wan-Sheng Zhao
Rok vydání: 2023
Předmět:
Zdroj: The International Journal of Advanced Manufacturing Technology. 126:145-162
ISSN: 1433-3015
0268-3768
DOI: 10.1007/s00170-023-10931-2
Popis: Observations of the discharge gap were conducted to investigate the discharge plasma motion in reciprocated traveling wire electrical discharge machining (RT-WEDM). It was found that the discharge plasma continuously slides on the surface of a workpiece. An oscillating moving heat source is proposed to better conform the characteristics of the discharge plasma motion. Based on the oscillating moving heat source, a novel thermal-fluid coupling model by adopting a level-set method was proposed to investigate the formation of a crater and the effects of machining parameters on the crater. Discharge plasma sliding, latent heat, and molten pool forces are comprehensively considered in the proposed model. Simulation and experimental results show that the sliding discharge plasma has a significant effect on a crater. At the end of a discharge, a considerable proportion of molten material remains in the molten pool. A high sliding speed of discharge plasma can lead to a low aspect ratio in a crater and a thin recast layer. Besides, due to the discharge plasma sliding, an increase in pulse duration can significantly increase the length of the crater and decrease the aspect ratio, while an increase in peak current can significantly increase the depth and volume of a crater. Simulation and experimental results also show that the morphologies of the simulated crater and experimental crater are consistent, verifying the feasibility and accuracy of the proposed simulation model in explaining the mechanisms of crater formation in RT-WEDM.
Databáze: OpenAIRE
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