L. S. Steele, Goodrich Corporation Aircraft Wheels and Brakes, Troy, OH; L. Mueller, Alcoa, Inc., Alcoa Center, PA; R. Sawtell, Alcoa Inc. Alloy Technology and Materials Research, Alcoa Center, PA
Aluminum aircraft wheels experience harsh and demanding operating conditions during service, including heat, carbon dust, runway and aircraft fluids, and high-energy braking events. Wheel alloy property design drivers include strength at ambient and elevated temperature, corrosion resistance, density, fatigue behavior, and fracture resistance. The combination of these material properties present in conventional wheel alloys such as 2014 and 7050 naturally drives the structural design of the wheel. A new wrought aluminum alloy, 2040, possesses an enhanced combination of these properties relative to 2014 and 7050 which results in reduced weight wheel designs. Alloy 2040 is targeted for its first commercial aircraft use in the near future. This presentation will review and compare the material property drivers of 2040 with both 2014 and 7050, including wheel roll-on-rim performance.
Summary: Aluminum aircraft wheels experience harsh and demanding operating conditions during service, including heat, carbon dust, runway and aircraft fluids, and high-energy braking events. Wheel alloy property design drivers include strength at ambient and elevated temperature, corrosion resistance, density, fatigue behavior, and fracture resistance. A new wrought aluminum alloy, 2040, possesses an enhanced combination of these properties relative to 2014 and 7050 which results in reduced weight wheel designs. It was developed for improved combinations of properties at and after exposure to moderate temperatures to replace 2014-T6. Alloy 2040 (Al-5Cu-0.8Mg-0.6Mn-0.5Ag-0.12Z) exhibits 8-40% improvement in static strength properties compared to 2014, depending on property. Strength at temperature and strength retention after a temperature exposure data will be presented for 30min, 10hr, and 100hr soaks. Fracture toughness along with smooth and notched bar fatigue properties will be discussed. A comparison of Roll-on-Rim life for both 2014 and 2040 forged aircraft wheels will illustrate the enhanced damage tolerance of 2040 over 2014 for two different wheel configurations. Alloy 2040 is targeted for its first commercial aircraft use in the near future.
