Effect of Cu / Mn Content and Homogenization Modes on ALTEK Alloys Strip Microstructure and Properties

Abstract This paper presents the results of a comprehensive study on the microstructure and physical-mechanical properties of strips produced from promising ALTEK system aluminum alloys (2Cu1.5Mn and 3Cu2Mn compositions) in a full thermomechanical processing cycle, including cold and hot rolling and annealing. The configuration of Al20Cu2Mn3 phase particles is directly determined by the prior thermal and deformation processing. Long homogenization annealing led to the formation of coarse (up to 1 μm) Al20Cu2Mn3 particles, which were unable to effectively inhibit polygonization and recrystallization processes. In contrast, homogenization annealing elimination promotes the formation of nano–dispersed Al20Cu2Mn3 particles, characterized by a significantly higher distribution density within the aluminum matrix. Dispersed plate–shaped particles, in particular, make the greatest contribution to strengthening, effective polygonization, and recrystallization suppression. The obtained results lead to the conclusion that the homogenization annealing stage is impractical for the basic ALTEK alloys, as this operation leads to thermal stability and strength property degradation.