Specific Features of Microstructural Evolution During Hot Rolling of the As-Cast Magnesium-Rich Aluminum Alloys with Added Transition Metal Elements

Abstract

This study addresses specific features of microstructural development during the rolling of the as-cast magnesium-rich aluminum alloys with added transition metal elements, such as Zr and Sc. For investigation purposes, three magnesium-rich aluminum alloys were chosen: 5182 without added Zr and Sc, 1565 ch with added Zr and 1570 with added Zr and Sc. Optical microscopy, X-ray texture analysis, electron microscopy, and electron backscattered diffraction methods were used in this study. This study demonstrates that two completely different patterns can be observed in the microstructure during deformation. Two zones with different subgrain sizes are formed when the alloy tends to recrystallize. Without recrystallization, the structure develops homogeneously. Recrystallization also has a significant effect on the texture formation. If recrystallization does not occur, a strong β-fiber texture is formed. However, this type of texture tends not to form during inter-deformation intervals when recrystallization occurs. Second-phase particles have the strongest effect on microstructural evolution during the hot deformation of the as-cast structure. Fine particles are capable of inhibiting recrystallization. Coarse particles initiate the PSN (particle-stimulated nucleation) mechanism and suppress the growth of the cubic texture component during recrystallization. An adequate combination of coarse and fine particles enables either better homogeneity of the structure distribution in the deformation center or better grain structure refinement.