Abstract: 5083 and 5083+0.1Zr aluminum alloys were melted and cast in laboratory by well crucible furnace, then rolled and annealed in the range of 100-450 ℃. The as-cast microstructure, fibre morphology of the plate, mechanical properties, corrosion resistance and the second phase particle compositions of the alloys were analyzed by means of metallographic microscope, microhardness tester, electronic universal testing machine and scanning electron microscope, so the effect of trace Zr addition on microstructure and properties of the tested alloys was studied. The results show that the addition of trace element Zr can refine the microstructure. Compared with that without Zr, the as-cast grain size of the 5083 alloy with 0.1Zr decreases from 123 μm to 73 μm. The trace addition of Zr can also reduce the size of the second phase Al₆Mn(Fe) particles, reduce the size of intergranular corrosion pits and improve the corrosion resistance of the alloy. Further, the trace addition of Zr can inhibit the recrystallization of the alloy plate, and there is no obvious recrystallization phenomenon when annealed at 300 ℃ for 1 h; and especially, after annealing at 250 ℃ for 1 h, the tensile strength of the 5083+0.1Zr alloy is 389.50 MPa, the yield strength is 215.62 MPa and the elongation is 18.2%, which still fully meet the application requirements.

Key words: 5083 aluminum alloy, trace element Zr, annealing, intergranular corrosion