High Strength Stress Corrosion Resistant Aluminum Casting Alloys Navy SBIR FY2010.2 Sol No.: Navy SBIR FY2010.2 Topic No.: N102-106 Topic Title: High Strength Stress Corrosion Resistant Aluminum Casting Alloys Proposal No.: N102-106-0594 Firm: QuesTek Innovations LLC 1820 Ridge Avenue Evanston, Illinois 60201 Contact: Abhijeet Misra Phone: (847) 425-8233 Web Site: www.questek.com Abstract: The United States Marine Corps (USMC) is pursuing high-performance aluminum castings for structural components of the Expeditionary Fighting Vehicle (EFV). Aluminum alloy A206 has been considered for these applications; however, this alloy is susceptible to hot tearing during casting, and has inferior stress-corrosion cracking (SCC) resistance. Under this proposed SBIR program, QuesTek Innovations LLC, a leader in the field of computational materials design, will design and develop a new high-strength SCC-resistant castable aluminum alloy for the waterjet inlet housing and/or steering bucket applications. The Materials by Designr framework will use QuesTek's state-of-the-art computational design tools for aluminum alloys, including custom thermodynamic and kinetic databases, microstructural evolution models, physics-based strength models, solidification and inoculation process simulations, and stress-corrosion cracking models. Our Phase I collaborators, Material Strategies, Inc. and Eck Industries, Inc. will assist QuesTek in Phase I alloy fabrication, castability testing and will provide process-related design expertise. In the program QuesTek will also partner with OEMs who will help define the material and process requirement matrix, and ultimately lead the alloy implementation. Concept feasibility will be demonstrated on model alloys fabricated in the Phase I program. Production-scale fabrication of the designed alloy will be demonstrated in Phase II. Benefits: High strength aluminum alloys are desirable for structural cast components, but are difficult to cast because of their hot tearing susceptibility. In addition, Al-Cu type alloys are susceptible to SCC in chloride environments that can result in costly unscheduled maintenance. The lack of hot tearing resistance also makes these alloys difficult to weld. The outcome of this SBIR program is the design and development of a new high strength castable and weldable aluminum alloy with SCC resistance. Enhanced hot tearing resistance and castability allows the cost-effective fabrication of the desired near net-shape structural components, eliminating the need for costly and non-practical process routes such as machining from forged blocks. Additionally, higher SCC resistance prevents SCC-related failures, thus saving USMC millions of dollars in SCC-related maintenance. Other project goals will include maintaining low alloy cost, achieved through a reduction in processing cost, and by licensing the alloy to multiple suppliers. In addition to naval and marine defense-related applications, the commercial aviation sector, as well as the automotive sector, will greatly benefit from a high-strength SCC-resistant castable aluminum alloy. Return