Analysis of flow field for ECM square deep hole with two-section square cone combination cathode.

Electrochemical machining technology is adopted to solve the thorny problem of square deep hole machining. The distribution of the electrolyte flow field in the electrochemical machining gap of the deep square hole is simulated with the COMSOL simulation software based on the establishment of the gap electric field and the mathematical model of the gap electrolyte flow field. The simulation results show that the electrolyte flow field distribution in the machining gap is uneven and the electrolyte is not full. Therefore, the cathode structure in the corresponding machining gap area is optimized by the c o s θ method. The two-section square cone combination cathode with the bi-directional liquid supply is designed, and two groups of 16 added liquid holes with a diameter of 1.5 mm, a slope of 20° and an angle of 22.5° are adopted to improve the flow field distribution. After optimization, the extreme value of current density on the anode surface of the workpiece is reduced from 9.4 to 1.7 A/cm2, which significantly improves the uniformity of current density distribution. Finally, orthogonal experiments are conducted with different voltages, duty cycles, inlet flow rates and feed rates to obtain the experimental results of square hole size and surface roughness. The machining process parameters are selected by the grey correlation method: voltage 17 V, duty cycle 55%, an inlet flow rate of 20 m/s and feed rate 0.4 mm/min. The dimensions of the specimens meet the product requirements, enabling stable processing of square deep holes, significantly shortening the cathode design cycle and optimising the cathode structure. [ABSTRACT FROM AUTHOR]