Effects of Environmentally Compliant Corrosion Inhibitors on Crack Growth Behavior of Aerospace Aluminum Alloys

摘要

Environmentally compliant inhibitor formulations are required for aluminum aircraft that incorporate long-lived corrosion protection attirbutes. Currently, hexavalent chromates in various forms are the corrosion inhibitor of choice. The new, environmentally compliant corrosion prevention technology is based on non-chromate corrosion inhibitors, some of which may have a deleterious effect on the crack growth behavior of the alloy. Prior to the transition of this corrosion protection technology to Air Force weapon systems, any deleterious effects on structural properties must be known. The effects of chromate inhibitors on the crack growth properties of aerospace aluminum alloys Al 2024 and Al 7075 have been previously identified and serve as the baseline for this study. Standard crack growth tests were performed on Al 2024 and Al 7075 samples with a variety of inhibitors. Corrosion inhibitors for study include several multicomponent non-chromate inhibitor formulations involving borate, molybdate, phosphate, silicate, etc., compounds.