Influence of annealing treatment on properties and microstructures of alumina dispersion strengthened copper alloy

Alumina dispersion strengthened copper（ADSC） alloy was produced by internal oxidation. The hardness, ultimate tensile strength and electrical conductivity measurements and microstructure observation on the produced 0.12%ADSC （0.24% Al2O3, mass fraction） and 0.25%ADSC （0.50% Al2O3） subjected to different annealing treatments were conducted. The results show that the microstructure of the produced ADSC is characterized by an uniform distribution of nano-Al2O3 particles in Cu-matrix; the particles range in size from 20 to 50 nm with an interparticle spacing of 30100 nm. The produced 0.12%ADSC can maintain more than 87% hardness retention after 900 ℃, 1 h annealing treatment; the recrystallization can be largely retarded and is not fully completed even after annealing at 1 000 ℃ for 1 h, followed by cold deformation of 84%; local grain growth can be observed after 1 050 ℃, 1 h annealing treatment. The results also show that increasing either the alumina content or cold deformation degree increases the hardness of the produced ADSC.