mixed metal baths

Q. We are interested in a cleaner that will perform well for mixed metal ultrasonic baths. We are cleaning titanium and cobalt chrome. What can you recommend?

A. As a general rule, mixed metal baths should be avoided. When metals are far enough apart on the galvanic potential scale, batteries can form and the plating out of metal oxides can result, manifesting in dark deposits. This occurs when you clean active metals in electrical and electrolyte solutions in contact with another metal at a different galvanic potential.