High-strength and high-conductivity in situ Cu–TiB2 nanocomposites

It is of significant interests to enhance the strength of Cu alloys while retaining their good electrical conductivity for broad applications. In situ incorporation of nano-phase into Cu alloys is a promising method for this objective. However, little success has been reported. In this study, we successfully fabricated in situ Cu–TiB2 nanocomposites by a molten salt processing and systematically studied their mechanical and electrical properties. During the processing, Al was used to react and introduce nano- and submicron-size TiB2 efficiently into the copper melt. Immiscible Fe was later added to recover the electrical conductivity through sequential solutionizing, hot rolling, and electrical conductivity-recovering. Detailed microstructure, phase, and electrical studies validate the feasibility of the proposed procedures to achieve high-strength and high-conductivity Cu(–Fe)-TiB2 nanocomposites. Cu-1 wt.% Fe-5 vol% TiB2 offers 554.3 MPa in ultimate tensile strength, 4.4% in ductility, and 62.4% IACS in electrical conductivity. The new method paves an effective way to synthesize and incorporate nano-phase into copper melt for high-performance Cu nanocomposites. •A scalable method for processing in situ Cu–TiB2 was proposed.•Al was added to introduce and disperse nano- and submicron-size TiB2 efficiently into copper melt.•Immiscible Fe was used to recover electrical conductivity through the proposed post treatment.•Cu-1 wt.% Fe-5 vol% TiB2 offers 554.3 MPa in ultimate tensile strength, 4.4% in ductility, and 62.4%IACS in electrical conductivity.