Abstract: For electrolytically etching the surfaces of integrally bladed rotors (blisks) (6) made of nickel-base material for aircraft gas turbines, auxiliary cathodes (10), in addition to the main cathodes (3) provided in the electrolyte (1), are arranged in the area of the blades (9) remote from the electric contact points at the rotor disk (7). The auxiliary cathodes are adaptable in shape, arrangement and size to the blade and disk geometry, so that a uniform current flow from all parts of the rotor connected as anode via the electrolyte to the main and auxiliary cathodes is produced and an intense and uniform etching effect is achieved. This ensures a reliable structural assessment in all rotor areas and in particular also in the area of the integral blading.

Abstract: For electrolytically etching the surfaces of integrally bladed rotors (blisks) (6) made of nickel-base material for aircraft gas turbines, auxiliary cathodes (10), in addition to the main cathodes (3) provided in the electrolyte (1), are arranged in the area of the blades (9) remote from the electric contact points at the rotor disk (7). The auxiliary cathodes are adaptable in shape, arrangement and size to the blade and disk geometry, so that a uniform current flow from all parts of the rotor connected as anode via the electrolyte to the main and auxiliary cathodes is produced and an intense and uniform etching effect is achieved. This ensures a reliable structural assessment in all rotor areas and in particular also in the area of the integral blading.