Improvement of dimensional uniformity on micro-dimple arrays generated by electrochemical micro-machining with an auxiliary electrode

Micro-dimples play an important role in improving the performance and reliability of mechanical systems. Through-mask electrochemical micro-machining (TMEMM) is a feasible alternative for generating micro-dimples. However, in TMEMM, the electrical field intensity at the edge is higher than that in other areas, which leads to poor dimensional uniformity of the micro-dimple arrays. In this paper, an auxiliary electrode with a positive potential was proposed to enhance the uniformity of distribution of the electrical field on the workpiece. Simulation results indicate that the auxiliary electrode with an appropriate potential is useful for improving the uniformity of the electrical field distribution. Experiments verify that with the potential of 10 V on the auxiliary electrode, the dimensional uniformity of the micro-dimple arrays was improved significantly, and the normalized dimensions of the arrays increased to 0.95. This approach is therefore effective in obtaining micro-dimple arrays with uniform dimensions.