Microstructure and mechanical properties of spray deposited Al-Mg-Li Alloy

The Al-5.5Mg-2.0Li-0.1Zr-0.2Sc alloy was produced by casting and hot extrusion process. The phase composition, microstructure, fracture morphology and mechanical properties of the alloy were analyzed by X-ray diffraction, differential scanning calorimeter, metallographic microscope, scanning electron microscopy, microhardness tester and tensile testing machine. And the effects of aging temperature (120 ℃ and 160 ℃) on the microstructure and mechanical properties of the alloy were studied. The results show that, the microstructure of as-extruded Al-Mg-Li alloys is fibrous-like. After solid solution and aging, reinforcement phase of δ′ (Al₃Li) and S1 (Al₂MgLi) precipitate from alloy after aging. The alloy reaches peak aging state after aging at 120 ℃/20 h, and the tensile strength, yield strength and elongation a 532 MPa, 476 MPa and 4.4 %, respectively.