Cathode
Posted on 11-03-2010The cathode is the electrode at which reduction takes place. In electrochemical machining the cathode is the negative electrode and is used as tool to machine the positive workpiece.
The choice of cathode material is defined by the required properties like hardness, machinability, (electro-) chemical resistance, electric conductivity, erosion resistance and by cost. Frequently used cathode materials are Stavax and Monel.
In some ECM processes, when using bipolar pulses, the cathode material has to be inert to the negative pulse (where the tool is working as anode). Using an inert material like platinum can solve the problem, but will raise the costs and also platinum is not completely inert in the ECM process. Another possibility is to coat the tool electrode with a conductive and inert coating.
Tags: Cathode, Cathode reactions