the strength in both alloys vary within u02dc 12 mpa in both l and t directions while no major differences are noted in the elongation values the paint bake response of the two coils is compared in fig1 this figure shows that the change of solutionizing temperature from 535 to 550 u00b0 c improves the paint bake response by about 6 to 19 mpa where most of the improvement is seen in the al6 alloy the paint bake response of the al5 alloy solutionized at 550 u00b0 c is around 148 mpa which is about 8 mpa better than its al6 counterpart the ys of the al5 and al6 alloys produced with and without batch interannealing are compared in fig1 the use of batch annealing reduces the ys in both the t4p and t8 2 tempers it is necessay that the alloys be solutionized at 550 u00b0 c to maximize the paint bake response of the alloys however it should be noted that the paint bake response of the al5 and al6 alloys solutionized at 535 u00b0 c is still comparable to the conventional aa6111 the n and r values of the two alloys are shown in fig1 as in the t4p temper the n values strain hardening index in both the alloys are.