Study Of Micro Groove Machining By Micro ECM

Electrochemical machining (ECM) is an anode dissolution process. ECM is widely used in airplane industry to machine engine parts due to no stress and recast layer remained in the machined surface. The significant advantage of ECM is no tool wear. To improve the machining accuracy, electrical pulse generator is used in ECM. Micro ECM has the ability to generate the micro features in electrically conductive materials. A nanosecond pulse generator is used in micro ECM to localize the electrical chemical machining within a narrow range. Micro features such as micro holes,3D micro cavities are machined successfully. To avoid the influence of the stray capacitance between the side of electrode and the side walls of machined features, the electrode is covered with an isolated layer when a hole is drilled or a disk-like electrode is used.Micro ECM is a complex material removal process. In this study, micro groove machining by micro ECM as an example, the influence of parameters (voltage, on-time and frequency of pulse generator, electrolyte flow, rotation speed of electrode, etc.) on the machining performance such as material removal rate (MRR) and accuracy is investigated.Total of 19 grooves were machined on a self-made micro ECM equipment using a nanosecond pulse generator. Experimental results were recorded and analyzed. It was found that the angle and the radius between the side wall and the bottom surface of a groove vary with the voltage and frequency of pulse, the rotation speed of electrode, electrolyte concentration besides of the MRR and surface roughness. The angles of right side and left side are different. The electrolyte system with double nozzle is proposed to shorten the geometrical deviation such as the corner and the taper of the right and left sidewall of a groove. The results are analyzed. It was found that the good surface quality of the 3D micro grooves was obtained with high shape precision and high efficiency by applying ultra short pulses and dilute dulfuric acid. Besides, the austenite grain can be seen clearly on the undersurface of the micro grooves and the surface roughness Ra of the finished surface can be less than 80nm. The radius of the corner which formed by the intersection of the side wall and the undersurface can be controlled under 8?m.