Abstract:Significantly increasing the strength of copper while sacrificing as little of its electrical conductivity as possible remains a challenging task. In this paper, a series of copper alloys with a lamella heterogeneous structure were produced by sintering Al2O3 dispersion strengthened copper alloy powders and pure copper powders, followed by cold rolling and partial recrystallization annealing. The former formed hard components and the latter formed soft components which were embedded in a matrix of hard components. The effect and mechanism of volume fraction ratio of soft/hard components on their mechanical and electrical properties were investigated. With an optimized 1/4 volume fraction ratio of soft/hard components, the as-prepared heterostructured copper alloys have good comprehensive properties of 468 MPa tensile strength, 89.5% IACS electrical conductivity and 8.4% uniform elongation. The obvious difference in mechanical properties and the strong mutual constraint between the soft and hard components caused a large number of geometrically necessary dislocations at the interface. These extra stored geometrically necessary dislocations contributed to extra strengthening and work hardening, thus improving the strength and ductility of heterostructured copper alloys. In addition, pure copper components scattered less of the free electron movement, thus maintaining a high level of electrical conductivity.