Microstructure and Toughness of High-Strength Aluminum Alloys

Abstract

The toughness of wrought, high-strength aluminum alloys is related to the amount, type, and morphology of coarse (larger than about 1 /i.m) constituent particles, intermediate size (about 0.02 to 0.5 fi,m) dispersoids, and fine (down to about 0.001 |u.m) precipitates. High toughness can be attained by minimizing the size and volume fi-action of constituent particles, increasing the interdispersoid distance, refining the intragranular precipitate in 2XXX alloys, and controlling the intergranular precipitate in 7XXX aUoys. For highest toughness in 7XXX alloy products where low residual stress is desired, rapid quenching followed by the minimum amount of cold work required for mechanical stress reHef is recommended.