Fundamental Investigation of the Retrogression and Reaging (RRA) of Commercial Al-Base Alloys and Its Effect on Stress Corrosion Cracking

摘要

The microstructure of 7075 Al, aged to the T6 and T76 temper conditions, has been carefully characterized with respect to the nature of the precipitate phases that exist in the matrix and in grain boundaries, and the parameters associated with their dispersions. The microstructural changes that occur during various retrogression and retrogression and reaging heat-treatments have been thoroughly documented. The possible consequences of these latter heat treatments on the stress-corrosion susceptibility and yield strength of Al 7075 are discussed. (Author)