Faradayic Electropolishing of Niobium in Environmentally-Benign Electrolytes

The International Linear Collider (ILC) requires microscale-smooth RF superconducting cavities fabricated from niobium. The task of polishing the cavities currently involves the use of toxic electrolytes that include hydrofluoric acid. It is desirable to find new methods of surface finishing that use environmentally benign electrolytes for increased worker safety. This project will develop and demonstrate a sophisticated electrically mediated polishing process, the Faradayic process, that will enable polishing of niobium cavities in near-neutral water-based solutions. This effort will include process development, equipment design, and construction of the equipment. Commercial Applications and other Benefits as described by the awardee: In addition to the ILC application, electrochemical polishing and machining processes for passive materials such as niobium, titanium, nickel-based alloys, and stainless steels that utilize environmentally friendly electrolytes should have wide applications in a variety of industries, including aerospace, medical, and automotive.