from the conferences organized by TANGER Ltd.
Low alloyed 1XXX series aluminum alloys are widely used due to their excellent electrical and thermal conductivity, high corrosion resistance, and superior formability. However, their relatively low mechanical strength limits their applicability in environments involving elevated temperatures. In applications where components may be exposed to thermal loads approaching 200 °C, additional softening can occur, even when prior mechanical deformation has introduced a degree of strengthening. To enhance thermal stability, alloying elements such as Zr are commonly added to promote solid solution strengthening and to form thermally stable Al₃Zr dispersoids that inhibit recovery and recrystallization. While these alloys are traditionally produced by direct chill (DC) casting, continuous casting (CC) has seen increasing adoption due to its higher processing efficiency. A known drawback of CC, however, is the potential development of through thickness inhomogeneities in mechanical properties, which can significantly affect the subsequent forming of thin sheets or thin walled products. In this study, an experimental EN AW 1050A alloy containing a small addition of Zr was produced via continuous casting and subsequently subjected to hot rolling and cold rolling to achieve a total thickness reduction of 80%, followed by annealing at 500 °C. Despite this thermomechanical treatment, the material exhibited microhardness variations of approximately 10-20% across the strip thickness. These results indicate that neither extensive deformation nor exposure to elevated temperature fully eliminates the intrinsic microstructural differences between the surface and central regions introduced during the CC process.
Keywords: Aluminum alloy, Continuous casting, Microhardness, Inhomogeneity, Recrystallization© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.