Effect of trace Sc and Zr on microstructure and properties of as-cast 5182 aluminum alloy

Abstract

Four groups of 5182, 5182-0.4 % Sc, 5182-0.1 % Sc-0.3 % Zr and 5182-0.3 % Sc-0.1 % Zr (wt.%) aluminium alloys were prepared. The microstructures of these alloys were examined using optical microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results showed that the addition of Sc leads to the effect of grain refinement, and adding both Sc and Zr makes this phenomenon even more obvious. The morphology and distribution of the second phase changed. The addition of Sc makes the tensile strength increase and the elongation decrease. Adding both Sc and Zr significantly improves the mechanical properties of the alloy. The tensile strength of 5182-0.3 % Sc-0.1 % Zr alloy reaches a maximum value of 223 MPa, and the Brinell hardness of the alloy reaches a maximum value of 88.7 HBW.