Thirty Years of Retrogression and Re-Aging (RRA)

摘要

The first work on Retrogression and re-Aging (RRA) was performed over thirty years ago by Cina and his colleagues in Israel, in an attempt to achieve high levels of both strength And stress-corrosion-cracking (SCC) resistance in 7075 Aluminum alloy, thus combining the best features of the T6 And T73 tempers. Their process, however, involved such short Heat-treatment times that its application would be effectively Limited to very thin section components that typically do not Exhibit SCC. Work at the NRC-IAR began in 1980, with the First goal being to explore modifications to the process in Order to make it amenable to thick section parts.