Computational Design of High-Strength Thermally-Stable Aluminum Alloy for Aircraft Wheel and Brake Applications

Aircraft wheels and brakes are subject to high energy braking events and harsh operating conditions. Constant improvements are being sought in key material properties for this demanding application in order to enable component weight reductions and reduce life-cycle costs. Under this proposed SBIR program, QuesTek Innovations LLC, a leader in the field of computational materials design, will develop a new high-strength thermally-stable 2xxx aluminum alloy with improved performance over incumbent 2014 and 2040 alloys, at lower or equivalent cost. The alloy will utilize a microstructural concept combining thermally-stable phases with traditional strengthening phases optimized for coarsening resistance and stability. The computational alloy design and development will implement a stage-gate process using QuesTeks state-of-the-art computational design tools for aluminum alloys, including custom thermodynamic and kinetic databases, well-calibrated microstructural evolution models utilizing PrecipiCalc software, physics-based strength models (validated with experiments), solidification process simulations, and stress-corrosion cracking (SCC) models. In the program QuesTek will partner with OEMs providing the role of voice of the customer to define the material requirement matrix, the processing requirements, and ultimately lead the alloy implementation. Concept feasibility will be demonstrated on prototype alloys fabricated in the Phase I program. BENEFIT: The inability of aluminum wheel alloys 2014 and 2040 to sustain mechanical strength after prolonged exposure to high temperatures during service is a critical issue. An alloy with better mechanical performance and strength retention results in component weight reduction, and improved durability.  The anticipated outcome of the SBIR program is a new 2xxx-type aluminum alloy for aircraft wheel and brake applications, with improved ambient strength and high-temperature strength retention over incumbent 2014 and 2040 alloys. In addition the alloy will have improved fatigue resistance that will enable reduced life-cycle costs. These 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 military aerospace applications, the commercial aviation sector, as well as the automotive sector will greatly benefit from a high-strength, thermally-stable aluminum alloy.