Cathodic etching to prepare metals for oxygen determination

Abstract

A cathodic etching method has been developed to clean the surfaces of metal samples prior to oxygen determinations. The sample becomes the cathode in a low-pressure argon-ion discharge. The argon ions bombard the surface of the sample and remove the oxide film by an etching process. The oxygen content of metal samples cleaned by cathodic etching is consistently lower than that of samples cleaned by filing. In addition, contamination from radioactive samples is minimised because the sputtered metal deposits on surfaces inside the etcher assembly.