![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
Abstract
The anodic passivation of tin in aqueous solutions of chromate, molybdate and tungstate has been compared. Passivity is favoured by concentrations greater than 102M and pH 5–9; chromates are most effective at 20°c and molybdate and tungstate at 40–60°C. Film compositions have been measured using coulometry and ESCA techniques. The films contain tin in two valency states and in the metallic form. Chromium is present predominantly as trivalent oxide but traces of metallic and hexavalent states were also detected.