AGING OF ALUMINUM-LITHIUM ALLOYS FOR IMPROVED COMBINATION OF FATIGUE PERFORMANCE AND STRENGTH

摘要

Aluminum alloy having an improved combination of properties are provided. In one aspect, a method for producing the alloy includes preparing an aluminum alloy for artificial aging and artificially aging the alloy. In one embodiment, the artificially aging step includes aging the aluminum alloy at a temperature of at least about 250 °F, and final aging the aluminum alloy at a temperature of not greater than about 225 °F and for at least about 20 hours. These aluminum alloys realize an improved combination of properties, including improved strength with at least equivalent fatigue crack growth resistance.