Solution chemistry of the electrochemical machining of titanium, niobium and tantalum

In the electrochemical machining process the electrolyte, in addition to conducting the required current, has the added function of removing the electrode reaction products—hydrogen from the cathode and metal oxide from the workpiece. This function is facilitated if close control is maintained over the pH of the electrolyte. Titanjum halides form clear solutions if the pH is less than 2 but precipitate if the pH exceeds 3·7. Niobium and tantalum halides were also studied.