Ultrahigh strength, thermal stability and high thermal conductivity in hierarchical nanostructured Cu-W alloy

Abstract

The wider application of copper alloys is challenged due to their relatively low strength and thermal stability. Here we report a nano-reinforcement dispersion strategy to achieved an excellent combination of ultrahigh strength, good ductility, high thermal stability and high thermal conductivity in a hierarchical nanostructured copper-tungsten (Cu-W) immiscible alloy. Our strategy relied on a uniform dispersion of nanoscale W particles (average size ∼ 7.6 nm) in ultrafine-grained Cu matrix (∼ 0.48 μm), by employing a molecular-level sol-gel synthesis and followed two-step reduction at low-temperature. The nanostructured Cu-W alloys exhibit a high tensile strength of 709 MPa, a total elongation of 20 % and a high thermal conductivity of 370 Wm−1K−1 at room temperature. The Cu-W alloy also has excellent thermal stability and the grain size hardly changes even after annealing at 800 °C for 1 h. Additionally, the nanostructured Cu-W alloy with numerous interfaces shows the potential to offer superior irradiation resistance. This work provides an effective strategy for constructing high-performance nanostructured immiscible alloys.