3D analysis of macresegregation in twin-roll cast AA3003 alloy before an after heat treatment

Twin-roll casting (TRC) allows production of sheets and strips with required thickness without subsequent homogenization or hot rolling and therefore has a high potential for industrial applications. One of the drawbacks of this method is a formation of inhomogeneous structure with central segregation. TRC prepared from 3003 aluminum alloy with 1 % Mn, 0.2 % Fe, 0.5 % Si, 0.2 % Cu and small addition of Zr (0.2 %) and Cr (0.1 %) was studied by X-ray computed tomography. Segregations in the material form as manganese, iron and silicon rich channels spread in rolling direction. Material annealed at 450°C exhibits diffusion of alloying elements from segregations into their surroundings and formation of voids or material with lower density in the center of segregation channels due to Kirkendall effect.