Fabrication and properties of low oxygen grade Al2O3 dispersion strengthened copper alloy

摘要

The low oxygen grade Al2 O3 dispersion strengthened copper alloy without hydrogen-fired expansion was fabricated by the technique of vacuum hot press and hot extrusion. The mechanical and electrical properties measurements and microstructures observation on as-hot extruded, as-cold drawn and as-annealed Cu-Al2O3 alloy were conducted. The results show that the addition of a suitable amount of boron in the alloy can lower the residual free oxygen content and then inhibit the hydrogen-fired expansion. The density, σb, σ0.2, hardness, δ and electrical conductivity of the alloy reach 8.86 g/cm3 (relative density of 99.6%), 340 Mpa, 250 Mpa, HB95, 24% and 93%(IACS) respectively after hot extruded with the extrusion ratio of 30: 1. Its properties have no change after annealed at 900℃ for 1 h. Its strength increases after cold drawing, while its ductility and electrical conductivity drop gradually.Various properties of the cold drawn alloy can recover to those of as-extruded after annealed at 900 ℃ for 1 h without the occurrence of recrystallization.