Method of minimizing strength anisotropy in aluminum-lithium alloy wrought product by cold rolling, stretching and aging

摘要

Strength anisotropy of aluminum-lithium alloy wrought products is reduced by subjecting these types of alloys to improved T8 temper practice. The wrought product, after solution heat treating and quenching, is subjected to a combination of cold rolling and stretching steps prior to aging. The cold rolling can range between 1 and 20% reduction with the stretching step ranging between 0.5-10%. The cold rolling step may be performed in one or a multiple of passes. When multiple passes are used, the cold rolling may be done in different directions to further enhance reductions in strength anisotropy for these types of alloys. An aluminum- lithium alloy wrought product subjected to the improved T8 temper practice has an increased minimum tensile yield stress throughout its thickness and in various directions to facilitate commercial application of the product in high strength applications.