Simulation study on cathode structure optimization of aluminum alloy thin-walled internal spiral deep hole electrochemical machining

Abstract

Abstract In order to solve the problems of easily distort and poor surface quality in machining aluminum alloy thin-walled internal spiral deep hole parts, a precision forming electrochemical machining (ECM) method was proposed. In this paper, the physical model of the pull-type downstream and pull-type countercurrent cathode was established, the simulation study on the flow field of the pull-type downstream and pull-type countercurrent cathode gap was carried out. The inclination angle of the cathode liquid supply hole was optimized. The simulation results showed that the flow rate of the pull-type downstream cathode electrolyte is 21% higher than the pull-type countercurrent cathode, the flow field is more uniform when the inclination angle of the cathode liquid supply hole is 30°. Using the self-developed large-scale horizontal electrochemical machining equipment, under the conditions of voltage 7.5V, current 1850A, composite electrolyte 10%NaCl + 9%NaNO3, electrolyte temperature 30°C, inlet pressure 1.2MPa and cathode feed rate 100mm/min, the surface roughness of Ra0.741µm and the forming accuracy of 0.035mm aluminum alloy thin-walled inner spiral deep hole stable machining was completed. The research shows that the cathode structure optimization simulation can effectively shorten the cathode development cycle and reduce the test cost.