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 mu m and 10 mu m, and the resolution of the machining was found to be dependent on the duration of the nanoscale pulses. Microstructures were also machined to 100 mu m 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. Published by Elsevier Ltd.