Roles of Sc and Ag Microalloying Elements in the Mechanical Properties of Al-Zn-Mg-Cu (Al7xxx) Alloy

In this study, we use microstructural investigation to examine the effects of Sc and Ag microalloying elements on mechanical properties Al-Zn-Mg-Cu-based (7050) alloy. Macroscopically, significantly reduce formation intermetallic particles S (Al2CuMg) T (Mg32(Al, Zn)49) stable η (MgZn2) phase in Al7050 addition, element facilitates precipitation η’ hardening phase, while impedes phase. As a result, trace addition enhances σUTS value alloy from 552 MPa 594 without lowering elongation (15.0% → 15.5%). contrast, tensile strength decreases 456 with element, increases 15.0% 21.0%.