Recrystallization kinetics and microstructural evolution in hot rolled aluminum alloys

The kinetics of recrystallization and texture evolution in hot rolled aluminum alloys 1050 and 5005 have been analyzed. The as-received samples were given isothermal annealing treatments at different temperatures and their recrystallization kinetics and texture evolution were obtained as a function of annealing temperatures and times. Two different methods were used to measure recrystallization kinetics - microhardness variations and mapping with Electron BackScattered Diffraction (EBSD) also known as Orientation Imaging Microscopy (OIM). Microhardness variations represent an average behavior against which the methods based on EBSD were compared. Intragranular orientation variation (short-range and long-range) was found to be an important parameter for partitioning EBSD maps into deformed and recrystallized regions. Comparable recrystallization kinetics were obtained from microhardness variations and EBSD. Microstructural Path Modeling (MPM) was used for analyzing recrystallization kinetics. Recrystallization in hot rolled aluminum alloys 1050 and 5005 was determined to be site-saturated and controlled by migration of high-angle boundaries.; The ability to partition deformed and recrystallized regions based on intragranular orientation variations provided an important tool for analyzing and understanding the texture evolution in deformed and recrystallized grains independently of each other. Rolling orientation components S and Brass exhibited very different effects on annealing. While the deformed S orientation was observed to decay very fast, Brass deformed grains remained stable to annealing. Recrystallized grains had Cube as the main texture component, which nucleated from the deformed Cube bands. The recrystallized Cube grains exhibited both a nucleation and growth advantage when compared to the other recrystallized orientations. Although the nucleation advantage of Cube recrystallized grains was observed to be present at all annealing temperatures, the growth advantage for these grains were present only at low annealing temperatures.