Electrochemical micromachining of Hastelloy B-2 with ultrashort voltage pulses

Electrochemical micromachining (ECMM) with ultrashort voltage pulses, a maskless all-electrochemical micro and nanofabrication technique, was used to fabricate microstructures on a corrosion resistant nickel-based superalloy, Hastelloy B-2,1 whose work hardening behavior makes it difficult to machine on the macroscale. This work presents a viable, strain-free micromachining strategy for this technologically important material. ECMM was used to machine microstructures to depths of 3 μm and 10 μm, and the resolution of the machining was found to be dependent on the duration of the nanoscale pulses. Microstructures were also machined to 100 μm depths, demonstrating the potential for the fabrication of high aspect ratio features using this technique. The ECMM was performed utilizing an apparatus consisting of standard electrochemical equipment combined with a custom electrical circuit that was constructed easily and at low cost.