Innovative Methodologies for the Development of a High Strength, Anodize-Free Corrosion Resistant, Aerospace Aluminum Alloys

Lightweight, high-strength aluminum alloys are widely used for structural components of aircraft and ships. However all high-strength aluminum alloys, such as 7050-T74, are susceptible to stress corrosion cracking (SCC) and general corrosion in chloride environments, and the repair and maintenance of corroded components is a major cost driver. As a result, most aerospace aluminum alloys are anodized to enhance corrosion resistance. Unfortunately, anodization can reduce fatigue strength by as much as 40%, add cost, and produces a dangerous hazardous materials waste-stream. In the Phase I SBIR program QuesTek Innovations LLC successfully designed unique high-strength aluminum alloys with nearly 100% better SCC resistance, equivalent or better pitting resistance, and equivalent or better strength over baseline 7050-T74 alloy in the short-transverse direction. Under this Phase II SBIR program, QuesTek will focus on the optimization, scale-up, and coating process selection of the Phase I alloy design and identify target components for application. At the end of the Phase II program, QuesTek anticipates generating the alloy property data required to initiate a Phase III component level fabrication and qualification program. In the program QuesTek is partnering with OEMs who will help define the material and process requirement matrix, and ultimately lead the alloy implementation.