Microstructure and tensile properties of A356 alloy with different Sc/Zr additions

Addition of rare earth elements for improving the tensile properties of aluminum alloys has attracted great attention. In this study, a systematic analysis on the microstructure and tensile properties of A356–0.13Ti alloys with different contents of scandium (Sc) and scandium/zirconium (Sc/Zr) after solution and aging treatment process was carried out. The addition of Sc/Zr into A356–0.13Ti alloys can greatly refine the grain size and modify the deleterious coarse eutectic Si structure and harmful acicular iron-containing phase morphology. As a result, the maximum value of strength (298 MPa) and ductility (elongation of 8.4%) are acquired by co-addition of Sc/Zr after solution and aging treatment process, which indicates that the tensile properties of A356 alloy are greatly enhanced by the synergistic effect of co-addition of Sc/Zr. Graphic abstract