Effect of Alloying Elements and Processing Parameters on Microstructure and Properties of 1XXX Aluminium Alloys

Direct chill casting (DCC) and twin roll casting (TRC) methods were applied to produce 1XXX series aluminium blanks with different contents of Fe, Si, Cu, and Mn elements. Different treatments, including homogenization, hot rolling, cold rolling, and annealing, were subsequently applied to produce the aluminium foil of 13 mu m in thickness. Results show that the casting process barely affects the tensile strength of the aluminium foil, while the fine particles of secondary phase introduced by twin roll casting has a positive effect on the elongation of aluminium foil. The coarse grain boundary intermetallic in ingots after DCC can be refined at homogenization temperature above 580 degrees C, and subsequently be broken into small particles through the following hot rolling process. The addition of Cu is better than that of Fe, Si, or Mn elements, as Cu solute atoms can increase the strain hardening rate. The foil thickness greatly affects the tensile properties during intermediate annealing process, which is related to the ratio of thickness to grain size. Room temperature storage causes deterioration of tensile properties of thin aluminium foil due to the recovery mechanism after application of very large strain.