Experimental setup for the investigation of the transport of different gas bubble sizes during electrochemical machining based on similarity theory using particle image velocimetry

The major advantage of electrochemical machining (ECM) is the ability to machine materials regardless of their mechanical properties such as hardness or temperature resistance. This property of the ECM process makes it ideal for processing difficult-to-machine materials such as high-performance nickel-based alloys and single-crystal alloys. However, it is difficult to predict a priori the appropriate tool electrode for a given workpiece contour. This is not only due to the constantly changing properties of the electrolyte during machining, but also to the transient nature of the working gap. To simplify tool design in ECM, a better understanding of the various phenomena that occur, such as gas formation and its propagation in the working gap, is necessary. This paper presents an experimental investigation of the transport of different gas bubble sizes during ECM by up-scaling the working gap according to the principles of similarity theory. The multiphase flow is analyzed using 3D particle image velocimetry, which will serve for validation of future simulation models.