Effect of pre-precipitation on precipitation behavior and recrystallization grain size of cold rolle

The effects of pre-precipitation on recrystallization grain size and precipitation behavior of the cold rolled 3003 aluminium alloy were investigated by means of electrical resistivity(measurements,) optical microscopy,scanning electron microscopy and energy differential spectrum.The results show that after the homogenization at 610℃ for 36h followed by pre-precipitation at 480℃ for 10h,a large amount of Mn-rich dispersoids in the 3003 aluminium alloy precipitate in grains,and the Mn content in solid solution decreases,which decreases the driving force for the following precipitation during recrystallization annealing.The temperature for the precipitation of the pre-(precipitated) alloy is about 50℃ higher than that of the alloy without the pre-(precipitation.) During the final recrystallization annealing,the precipitation of Mn-rich dispersoids takes place in the recrystallized matrix,which retards the growth of the recrystallized grains as well as the pre-precipitated particles,and a fine recrystallization grain structure is obtained.