A Redox Printing Technique for the Study of the Electronic Conductivity of Anodic Oxide Films on Valve Metals

Abstract

A printing method using iodide‐starch as the redox indicator in a solidified electrolyte was developed for applications to various valve metals and their anodic oxide films. It was used to study the electronic conductivity of anodic oxide films on tantalum and niobium and to detect defective sites in oxide films on aluminum. Applied to titanium, zirconium, and silicon, as well as the other valve metals, the technique was used for an evaluation of the surface condition of the metal substrates. The technique also was useful in cases where the oxide films corroded under the influence of the printing electrolyte.