TEM investigation of age-hardenable Al 2519 alloy subjected to stress corrosion cracking tests

The influence of changes in chemical composition and pre-aging deformation on the resistance to stress corrosion cracking in the age-hardenable aluminum alloy 2519 was investigated by transmission electron microscopy. The improvement of this resistance may be accomplished by keeping the Cu concentration on the lower side of the allowed limit for the 2519 alloy. Also, plastic deformation prior to aging, comprising both cold rolling and stretching, seems to be beneficial since it promotes a more homogeneous distribution of the precipitates and reduces the number of precipitates on the grain boundaries and thus shrinks the total volume of precipitation-free zones at grain and subgrain boundaries.