Solution treatments of plates of Al-6.2Zn-2.3Mg-2.3Cu aluminum alloy

摘要

Solution treatments(ST) of the 60 mm-thick plates of AI-6.2Zn-2.3Mg-2.3Cu super-high strength aluminum allay have been studied by DSC,OM and SEM-EDX. The results show that the hot-rolled plate of this alloy contains of the phases containing Zn with melting temperature of 477 ℃ and the coarse S phase (Al_CuMg) with melting temperature of 489 ℃. The former can dissolve into the matrix of the alloy after ST at 470 ℃ for 1 h,but the latter can only partly dissolve into the matrix of the alloy at 470 ℃,which cannot dissolve completely even at 480 ℃,so the temperature of second-stage ST should not be beyond 489 ℃ following first one at 470 ℃ for 1 h.For industrialized treatment,the double-stage ST of 470 ℃ x 1 h+480 ℃ belong to the procedure suitable to 60 mm-thick plate of this alloy.