Copper content also plays a role. Consider the
comparison of alloys 7075 and 7050, where 7050
has a higher copper content. ForWtemper, 7050
is more susceptible to IG forms of corrosion
(SCC, IGC, exfoliation), than 7075. It is believed
that the higher-copper alloy retains more copper
in grain boundary precipitates during the quench