Introduction Electrochemical machining (ECM) is a non-traditional metal shaping technique known and applied since the middle of the last century. Industrially, it is mainly used for shaping difficult-to-machine metals and alloys and complex shapes, e.g., turbine blades, parts for aerospace1 and automotive industry2 or biomedical industry.3 Characteristics are the polished surfaces and the unconventionally high current densities (>100 A cm−2) applied for controlled anodic metal oxidation.
