Nickel-based superalloys have been widely used in the aerospace and military industry due to their unique physical and chemical properties. However, the commonly used mechanical milling methods of nickel-based superalloys have some disadvantages, such as low material removal rate, high cost, and severe tool wear, which are prominent when processing integrated disks, turbine disks, gearboxes, connecting frames, and return cabins in the aerospace field. To solve these problems, high-efficiency electrical discharge assisted arc milling of nickel-based superalloy is studied, and a high-purity graphite tube is used as the tool electrode in this research. The outer working fluid is high-speed compressed air, and the inner working fluid is deionized water. A self-developed electrical discharge assisted arc milling CNC machine tool is used. The effects of different machining parameters on the material removal rate, relative electrode wear rate, and machining error of superalloy GH4169 are studied. The microstructures of the machined workpiece surface are also observed. The experimental results show that the material removal rate of nickel-based superalloy GH4169 can reach 11 523 mm3/min, with the relative electrode wear rate of about 1.5%, and the machining cost is much lower than that of conventional mechanical milling.
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