Anodic Behavior of Titanium in Aqueous Media

Abstract

Galvanostatic anodization of titanium has been studied in N2-de-aerated, 1 normal solutions of NaOH, Na2SO4, H2SO4, HCI, HClO4, HNO3, and H3PO4 at 25 C at current densities ranging from (4 to 50) 10−6 Acm−2. Valve metal behavior was evident in all media. The parameters of the empirical law are calculated; both were highest in the NaOH solution and lowest in the H2SO4 solution. From unitary formation rate values, the following arrangement of passivation was obtained: NaOH > Na2SO4 > HClO4 > HNO3 > HCl > H3PO4 > H2SO4. The open circuit potential rate of increase with oxide accumulation parallels the passivation property of the medium. Oxide building continues in acid media above the arrest potential.