Abstract: Dissolution behavior of residual phases at grain boundaries during the solution process of 2A12 alloy was studied by using techniques such as differential scanning calorimetry (DSC), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results show that the overburning temperature of the 2A12 alloy is 509.6 ℃, and the main phases in the rolled state alloy are non-equilibrium solidification eutectic phases of Al, Cu, and Mg. During the solution treatment process, the non-equilibrium eutectic phase in the alloy gradually melts and spheroidizes, and the segregated elements dissolve into the matrix. As the solution treatment temperature increases, the hardness of the specimen increases. This is because more non-equilibrium eutectic phases in the specimen dissolve into the matrix, increasing the solubility of the matrix and increasing the number of solute atoms dissolved into the solvent lattice, resulting in an increase in hardness.

Key words: 2A12 aluminum alloy, solution treatment, residual phase