Investigation of inner-jet electrochemical face grinding of thin-walled rotational parts

A shaver cap is a typical thin-walled rotational part, and the processing performance of its torus surface has an important impact on the cutting efficiency, sharpness and working noise of the shaver. Electrochemical face grinding (ECFG) is a promising machining method in the fabrication of difficult-to-cut thin-walled parts. However, the flow field distribution in the interelectrode gap can vary, and the effect of electrochemical levelling can suffer during the electrochemical face grinding of multiple torus surfaces. Moreover, the nonuniform distribution of abrasives and the differences in coequal height can generate severe grinding marks on the torus surfaces. In this work, superimposed linear and circular translational movements were proposed to improve the electrochemical grinding performance of multiple torus surfaces. Based on a simulation of a gas-liquid two-phase flow field, the effects of grinding head rotational speed and superimposed linear and circular translational movements on the flow velocity and void fraction were investigated. Moreover, the variations of machining allowance, flatness and surface roughness on the torus surfaces were experimentally studied. The flow field simulation and experimental results showed that the flow velocity and void fraction were changed periodically in the machining area by superimposing translational movements, which was conducive to eliminating flow field defects and improving the electrochemical levelling performance. Moreover, the fluctuations of electrolyte flow velocity and void fraction in the machining area were small when the circular translational movement was superimposed, and a synergistic effect of dissolution and grinding was noted. The overall flatness of the torus surfaces was only 3.93 μm, the maximum height of the surface roughness profile was 0.797 μm, and there were no obvious grinding marks on the inner and outer torus surfaces under the optimized circular translational parameters.