Effect of hot deformation on recrystallization behavior of Al4.5Mg alloy

Hot rolling parameters, i.e., rolling strain, strain rate, and temperature, have important effects on the recrystallization behavior of Al-4.5Mg hot band. Since the hot band microstructure and texture have significant influence on the mechanical property anisotropy and formability of the final products it is important to control the hot rolling process to achieve the target quality of the hot band. In the present work, the effect of hot deformation on recrystallization behavior of Al-4.5Mg alloy was studied. Laboratory rolling experiments were performed and hot rolling process data was collected to study the alloy microstructure and texture evolution during hot rolling on a multi-stand tandem mill. It was found that the restoration mechanism was closely associated with the hot rolling parameters, which significantly affected the stored energy and recrystallization microstructure and texture of the alloy. Average strain rate sensitivity (ASRS) was proposed to study the flow stress change during hot rolling. It was found that ASRS was a function of normalized average strain rate (NASR). In addition, a close correlation between ASRS and volume fraction of cube texture was found, which indicated that the development of the cube texture was related to the restoration mechanism involved in the deformation. A well-controlled hot rolling practice effectively improved the cube texture of the Al-4.5Mg alloy hot band.