In Phase I, technical and commercial feasibility was demonstrated for the application of friction stir processing (FSP) following by superplastic forming (SPF) of a 5083 aluminum alloy, and for FSP following by room temperature bending. An application showing significant promise for FSP followed by SPF is an aluminum water tight door. The use of FSP followed by SPF enables a significant part count reduction, which will yield significantly lower costs. In addition, this combination of technologies will result in a significant reduction in welding, thus reducing distortion and improving quality. In phase II of this project, FSP and SPF will be optimized for production application of these technologies. In addition, a prototype door will be fabricated. This part will be installed by the ship builder for fit and functionality testing purposes. A sponsor and application have also been identified for FSP followed by room temperature bending. The team is proposing that research and development work be carried out for this application. This would involve performing FSP and understanding its room temperature mechanical properties, similar to Phase I for the door application. In addition, a prototype part will be fabricated and installed as part of the proposed Phase II project.
Benefit: The most significant benefit of FSP followed by SPF will be the eventual implementation of a significantly lower cost fabrication method for moderate sized aluminum welded structures where there is a significant number of detail components. The new technology will enable use of formed components, rather than cut and welded structures, allowing for significant part consolidation. In addition, improved quality should result, since less welding and a lower distortion welding process (friction stir welding) will be used. Applications for this technology include Naval water-tight doors (as will be pursued in Phase II), as well as other closures. Similar applications also exist in other industries including, yachts, and pleasure boats. In addition, large land transportation vehicles such as dump trucks, cement trucks, military vehicles, etc. have a significant number of potential applications. As mentioned, FSP can also be used to enable bending of thick section aluminum in tighter radii at room temperature. This can reduce fabrication costs in a large variety of applications. Similar to FSP followed by SPF, this solution can yield significant part count reduction and elimination of a significant amount of welding. Flanged stiffeners are one such application in the Navy and marine industry. Other industrial applications include armored vehicles, heavy and light duty trucks, and trains, to list a few.
Keywords: fine grain structure, fine grain structure, Friction Stir Processing, Robot, temperature, Optimization, Aluminum, Bending, Feasibility, grain size, Commercialization, superplastic forming, strain rate, Superplastic, FSP
