This master’s thesis investigates the recrystallization of two aluminum alloys: commercially pure aluminum EN AW-1050A and the manganese-containing alloy EN AW-3102. The aim of the research was to comprehensively evaluate the influence of sample thickness, as well as different annealing temperatures and times, on the kinetics of recrystallization, monitored through measurements of electrical conductivity, differential scanning calorimetry (DSC), and metallographic analysis.
In the experimental work, samples of various thicknesses were annealed at 450 °C, 475 °C, and 500 °C. Electrical resistivity measurements enabled continuous monitoring of microstructural changes and the progress of recrystallization, while DSC analysis detected thermal transitions associated with the process. In addition, metallographic examinations under bright field and polarized light confirmed the evolution of the microstructure.
The results show that recrystallization in commercially pure aluminum proceeds faster and at lower temperatures compared to the manganese alloy. The presence of manganese slows down the process, raises the recrystallization temperature, and results in a less homogeneous microstructure due to the inhibition of grain boundary movement. Apart from chemical composition, sample thickness also plays an important role – in thicker samples, recrystallization proceeds more slowly due to less efficient heat transfer into the interior.
The study confirms that electrical resistivity measurements are a reliable and sensitive method for monitoring recrystallization, as changes in electrical conductivity correlate well with DSC results and metallographic observations. The findings contribute to a better understanding of the relationship between microstructure, electrical properties, and process parameters, which is essential for optimizing industrial processing of aluminum alloys.
|
