Evaluation of the Effects of Contamination by Silicates of Anodizing Seal Water

Abstract : An evaluation of the effects of contamination by silicates in the seal water on chromic acid anodized aluminum was performed. The results of the standard salt spray test indicate that the resistance to corrosion was drastically reduced as the silicates increased above 4 parts per million. The amount of corrosion obtained was in proportion to amounts of silicates from 3 to 10 parts per million. No effect was found on adhesive bond strength as measured by T-peel tests, when rinsing, following chromic acid anodizing, with water containing 1 to 100 parts per million of silicate.