Influence of Intermittent Aging in AA7075 Aluminum Alloy

Heat treatable AA 7075 Aluminum alloys have been used especially in the aerospace industry for several years for their high specific strength. The demands in lighter aerospace or road vehicles like electric cars are today's major concerns. In this study, it is observed for how far the strength can be increased for this reason the influence of intermittent aging in AA7075 Aluminum alloy investigated. Rolled mill product of stock AA7074 Aluminum alloy samples were heat-treated for T6 conditions following a homogenization at 500 oC for 96 hours, and solution treatment at 500 oC for 4 hours and quenching in water. Aged at 120 oC for 24 hours and quenched. After the T6 heat treatment, an additional aging heat treatment so-called T6I4 was done at 100 oC for 2, 4, and 6 hours. The T6I4 heat-treated AA7075 alloys' microhardness values were incrementally increased by the intermittent aging heat treatment. The maximum increase rate was achieved with secondary aging at 100 oC for 6 hours, 51 % more according to the T6 condition.