Abnormal Recrystallization Behavior of High Purity Aluminum Foil

The influence of heating rates on recrystallization behavior of high purity aluminum foil was systematically studied in the present paper. The result shows that the recrystallized sample experienced a low heating speed (180 degrees C/h, holding at 180 degrees C for 1 hour and then heating to 500 degrees C) has an smaller average grain size than that of sample with a high heating speed (put the sample in the furnace at 500 degrees C), which greatly differs from the general recrystallization behavior of typical metals. The recovery before recrystallization is suspected to be closely related with the abnormal recrystallization behavior. Most stored energy releases during recovery of annealing with low heating speed. Our result suggests that the heating speed is an effective way to modify the grain size of high purity aluminum foil.