Microstructural evolution and mechanical properties of an ultrahigh-strength Al−Zn−Mg−Cu alloy via powder metallurgy and hot extrusion

Abstract

In this work, a novel ultrahigh-strength Al−10Zn−3.5Mg−1.5Cu alloy was fabricated by powder metallurgy followed by hot extrusion. Investigations on microstructural evolution and mechanical properties of the fabricated samples were carried out. The results show that the grain size of sintered samples matches with the powder particles after ball milling. The relative densities of sintered and hot extruded samples reach 99.1% and 100%, respectively. Owing to the comprehensive mechanism of grain refinement, aging and dispersion strengthening, the ultimate tensile strength, yield strength and elongation of the Al−10Zn−3.5Mg−1.5Cu alloy after hot extrusion and subsequent heat treatment achieve 810 MPa, 770 MPa and 8%, respectively.

Keywords

powder metallurgy / Al−Zn−Mg−Cu alloy / ultrahigh strength / hot extrusion

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