Microstructure, mechanical properties and electrical conductivity of Cu-12 wt.% Fe microcomposite annealed at different temperatures

The Cu-12 wt.% Fe microcomposite of filamentary composite structure was prepared by heavy cold drawing. The microstructure was observed, and the mechanical properties and electrical conductivity were determined for the microcomposite annealed at different temperatures. Annealing at temperatures lower than 300 degrees C results in slight decrease in the strength and hardness and a certain increase in the conductivity. Obvious recrystallization occurs in the filamentary structure at higher than 400 degrees C. The filaments are basically replaced by equiaxial recrystallized grains at higher than 500 degrees C. The strength and hardness markedly decrease while the conductivity markedly increases with annealing temperatures from 300 to 600 degrees C. However, the conductivity decreases with annealing temperature from 600 to 700 degrees C. A suitable matched relationship between the mechanical properties and electrical conductivity can be obtained if the boundary migration of fine recrystallized grains is only restricted within the filaments of the heavily deformed structure during annealing. (C) 2008 Elsevier B.V. All rights reserved.