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.

Microstructure and Mechanical Properties at Elevated Temperature of Powder Metallurgy Al-Zn-Mg-Cu Alloy Subjected to Hot Extrusion

“…Figure 3b shows the calibration of the diffraction pattern. Figure 3b shows that the black phase was γ-Al 2 O 3 , which is consistent with previous studies [27]. Figure 4a-c show the OIM of the tensile BL samples at 250, 350, and 450 °C.…”

“…Figure 3b shows the calibration of the diffraction pattern. Figure 3b shows that the black phase was γ-Al2O3, which is consistent with previous studies [27]. Figure 3a shows TEM micrographs of the BM alloy, which consisted of a large number of black particles (less than 100 nm) with dislocation tangles.…”