Simultaneous improvement of electrical conductivity and mechanical property of Cr doped Cu/CNTs composites

Abstract

Acquiring high electrical conductivity and good mechanical property is a key issue for Cu/CNTs composites, which affects their potential applications in electrical material field. In this study, Cr was induced in the Cu matrix to enhance the interfacial bonding. Different amounts of Cr were chosen to thoroughly investigate their effect on the interface structure, the electrical conductivity and the mechanical property. By tailoring the combined effects of good densification, uniform dispersion of CNTs, moderate amount of carbide at the Cu/CNTs interface, strong interfacial bonding force and suitable Cu matrix microstructure, the good overall performance was obtained in a (Cu-0.07 wt.%Cr)-0.5 wt.%CNTs composite. The addition of trace amounts of Cr leads to in-situ formation of an appropriate amount of nano chromium carbide (Cr3C2) at the Cu/CNTs interface, which improves the interface wettability and benefits the current transfer and load transfer, and hence improves the conductivity while increasing the hardness.