Abstract: Extruded spray formed 1420 Al-Li alloy was solution treated at different temperatures for different time. The microstructure and mechanical properties of the alloy were analyzed by optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and electronic universal testing machine. The results show that a large number of Al₃Li and AlLi particles are distributed in the extruded alloy. After solid solution treatment at 450 ℃ for 0.5 h, the alloy can obtain fine microstructure and good comprehensive mechanical properties, with the average grain size being 2.91 μm, the second phase particles dissolved into the matrix, the tensile strength and the elongation being 377.47 MPa and 17.3% respectively, and the fracture mode of the alloy is ductile type. With the increase of solution treatment temperature and time, the cracks originate from the defects and propagate in transgranular mode.

Key words: 1420 Al-Li alloy, solution treatment, spray forming, microstructure, mechanical properties