Trivalent chromium for enhanced corrosion protection on aluminum surfaces *

SummaryThe trivalent chromium pretreatment formulated and invented by NAVAIR performs very well for replacing hexavalent chromium on aluminum. Its performance varies depending on the type of detergent and its concentration, temperature, and cycle time. Also important is the surface activation and the type of acid and/or deoxidizer that is used for the application. However, the most important factor is the type of aluminum alloy undergoing chromate conversion coating. It was concluded from the study that 2024 is the most difficult alloy due to its metallurgical content; if satisfactory results can be obtained for 2024, then it would not be so difficult to achieve successful results for other aluminum alloys.The EPA, when added to a standard trivalent chromium pretreatment (NAVAIR) bath, exhibited outstanding performance in NSS' testing. This additive is designed to enhance corrosion resistance of an aluminum alloy for trivalent chromium pretreatment performance. An EPA offers consistent corrosion resistance performance for difficult alloys, such as 2024. It is an additive that improves standard NAVAIR trivalent chromium application on aluminum for robust performance.It is sufficient to say that the most important aspect of using this newly developed, patented additive for trivalent chromium pretreatment its effective and consistent corrosion-resistance performance.