Simultaneously Improving Strength and Ductility of Mg−3Li−8Gd−2Y−1.5Ag Alloy by Solution Treatment and Hot‐Rolling Process

The microstructure and mechanical properties of Mg−3Li−8Gd−2Y−1.5Ag (wt%) alloy at as‐cast state, as‐solution state, and as‐rolled state (three rolling reductions of 30, 50, and 70%) are investigated. With the increase in solution time at 520 °C, the dissolution of Mg 24 (Gd,Y) 5 phase along the grain boundaries and the coarsening of grain size occur. The solution parameters of 520 °C/4 h are chosen in combination with microstructural evolution, grain size, and microhardness. The dynamic precipitation of irregular spherical‐like β 1 , needle‐like β′, fine β, and twins is observed after 30% hot rolling at 450 °C. With increasing the reduction to 70%, the number of β 1 , β′, and twins increases and massive stacking faults (SFs) appear in the twins. The strength and ductility of Mg−3Li−8Gd−2Y−1.5Ag alloy are simultaneously improved by the combination of solution treatment and hot‐rolling process due to the precipitation strengthening of β 1 and β′, the formation of twins and SFs, and the fragmentation of Mg 24 (Gd,Y) 5 phase along the grain boundaries.