Electrical and mechanical properties of a Cu-Cr-Zr alloy aged under an imposed DC current and static magnetic field

Abstract

In this paper, Cu-0.41wt.%Cr-0.21wt.%Zr alloy is subjected to an isochronal aging treatment with a DC electric current (100A/cm2) and a static magnetic field simultaneously imposed. The alloy in the form of plate with a thickness of 2 mm is solid-solution-treated and cold deformed with a total area reduction of more than 98% before aging. The results indicate that the conductivity and micro hardness of the sample are significantly improved by the imposed electric-magnetic field. The conductivity of the sample increases with magnetic flux density (MFD) improving, especially at a lower aging temperature (350 ℃), and a maximum improvement of 22.1% IACS in conductivity could be obtained with a 10 T magnetic field. For the property of micro hardness, it increases with MFD increasing at a lower aging temperature (350 ℃), while at a higher aging temperature, it first increases and then decreases with MFD increasing. The effects of the DC current and magnetic field on the microstructure of the alloy are investigated by transmission electron microscopy. A lower dislocation density and more Cr precipitation are observed under electric-magnetic couple field than under the DC current only. It indicates that the electric and magnetic fields enhance the aging process of Cu-Cr-Zr alloy distinctly. According to the experimental results, we believe that the main mechanism of the influence of electric and magnetic fields on the Cu-Cr-Zr alloy is that the magnetic field enhances the interaction between solute atoms, vacancies, dislocations and electron wind force, thereby intensifing the effect of the dc current.