Evolution of eutectic intermetallic particles in DC-cast AA3003 alloy during heating and homogenization

The evolution of primary particles in DC cast 3003 alloy during heating and homogenization at 600 degreesC has been investigated quantitatively. The size, area fraction and number density of the particles as well as the electrical conductivity of the alloy have been measured. Different mechanisms, breaking up, growth and coarsening, compete in the evolution of the primary particles during the heating and homogenizing process. The size, area fraction and Mn/(Mn + Fe) ratio of the particles increase with homogenization time. The precipitation of Mn onto the particles from the supersaturated matrix and dissolution of fine dispersoids play an important role in the size and composition evolution of primary particles during homogenization. The fraction of alpha-Al(MnFe)Si particles transformed from Al-6(Mn,Fe) increases with heating temperature and homogenization time. (C) 2002 Elsevier Science B.V. All rights reserved.