Abstract: Effect of heat treatment process on microstructure and properties of 8111 alloy produced by casting and rolling process was studied. The results show that after cold rolling and homogenization treatment, the microstructure uniformity of the cast-rolling sheet is improved, the chain like second phase disappears, and the grain morphology changes from fiber to fine equiaxed recrystallized grains. With the increase of annealing temperature, the microstructure of the aluminum foil undergoes a process of recovery, recrystallization and grain growth. The recrystallization is completed when annealed at 330 ℃ for 2 h, with an average grain size of about 42 μm. When the annealing temperature is at 360 ℃, the average grain size is the largest, about 45 μm. Within the studied annealing temperature range, there was no significant change in the morphology of the second phase compound in the aluminum foil matrix. With the annealing temperature increasing, the tensile strength of the aluminum foil shows a decreasing trend, reaching the minimum value of 87 MPa when the annealing temperature is 360 ℃, while the elongation shows a trend of first increasing and then decreasing, reaching the maximum value of 10.2% when the annealing temperature is 330 ℃, and the electrical conductivity shows a trend of first increasing and then decreasing, basically unchanged when the annealing temperature is 330-360 ℃.

Key words: 8111 aluminum alloy, microstructure, electrical conductivity, mechanical properties