Characteristics research of different electrode tip shapes by electrodeposition for micro slot ECM

Nickel-based superalloy René 77 is a difficult-to-cut material. The alloy contains elements such as chromium, cobalt, molybdenum, aluminum, titanium, and niobium, so it has good mechanical behavior. René 77 has high strength, plasticity, and stable structure at high temperature. Therefore, it is commonly used in components that need to withstand high temperatures, such as turbine blades for aircraft. The study uses electrochemical micro-machining (Micro-ECM) to generate slot on the René 77. First of all, the research uses the fixture module to hold the cathode, and add insulating layer to the sidewall of the tool electrode, and perform electrochemical machining (ECM). However, the insulating layer on the electrode will peel off after ECM. Therefore, to solve this problem, the research uses electrodeposition to form a nickel layer at the bottom of the electrode. Nickel has strong passivation ability and excellent corrosion resistance. After that, two different electrodes are used in ECM, which are electrodes with electro-deposited coating and without. At the same time, the research uses different machining parameters in ECM. Finally, observe the surface condition of René 77 and study the effect of different electrode tip shapes on the insulating layer. The results show that the electro-deposited coating can protect the insulating layer on the electrode.