HARDNESS TESTING OF Al-Mg SLABS

In this work, the hardness homogeneity of aluminum Al-Mg alloy slabs produced with semicontinuous casting process from 6 different charges was investigated. The evaluation of hardness homogeneity was carried out on the front and rear cross-sectional plates of the slabs at locations determined by a statistical design of experiments (“Latin square”). Previous studies have shown that the hardness depends on the location of the test and also correlates with the technological conditions. Therefore, hardness measurements were carried out according to the Vickers method at different distances from the edge of the plate: 1 mm, 2 mm, 5 mm, 10 mm and 20 mm. The hardness of the tested aluminum alloy plates decreases in both the height and width of the plate from the edges to the center, following the polynomial behavior. The hardness decreases from the edge up to a distance of 5 mm, after which the hardness equalizes for both for the slabs’ fronts and rears.