Experimental study and parameter optimization on sustainable and efficient machining GH4169 with rotating short arc milling method

Low processing efficiency and environmental pollution hinder the development of electrical discharge machining (EDM). To address this issue, a sustainable and efficient EDM method under compound field, namely rotating short arc milling, is proposed in this study. The magnetic field and high-pressure flow field of dielectric facilitate the removal of debris from discharge gap. Tap water is used as the dielectric to reduce pollutants generated during processing. Under the compound field, a portion of debris adheres to the machining end of the tool electrode to form a protective layer and participates in the discharge machining as a part of the tool electrode, which can reduce the tool electrode wear. This study describes the principles of this method to achieve high material removal rate (MRR), low tool electrode wear rate (TEWR), and environmentally friendly dielectric. Besides, a series of experiments are conducted to study the motion characteristics and resistance characteristics of rotating short arc, the influence of processing parameters on the machining performance of GH4169 superalloy. The results show that the machining voltage, machining depth, and magnetic field strength are the three most important factors that affect the efficiency and sustainability of rotating short arc milling. Furthermore, the optimal processing parameter combination is obtained by using gray relational analysis method to optimize the machining process in terms of high efficiency and environmental protection.