Thermal and electrical properties of W–Cu composite produced by activated sintering

In this work, nearly full density W–23.5 wt.% Cu composite was fabricated by activated sintering with Zn additive. Because of low melting point and high saturated vapor pressure for Zn, Zn additive was introduced into W–23.5 wt.% Cu composite to enhance the densification of W–Cu composite. The effects of relative density, Zn additive contents, microstructure and fractographs on thermal conductivity, electrical conductivity and coefficient of thermal expansion were evaluated by scanning electron micrograph, energy disperse spectrum, X-ray photoelectron spectroscopy and Archimedes method. It was found that adding Zn additive led high relative density for W–Cu composite while thermal conductivity and electrical conductivity were preserved at good values which were 198.5 W m−1 K−1 and 1.44 × 106 (Ω m)−1, respectively. The fractographs of W–Cu composite indicated the presence of strong grain-boundaries, which was beneficial to the thermal conductivity and electrical conductivity. The coefficient of thermal expansion was decreased to appropriate value from 9.58 × 10−6 to 8.75 × 10−6 K−1 by controlling Zn additive content.

► When 2.0 wt.% Zn additive is added, the thermal is 198.5 W m−1 K−1. ► When 2.0 wt.% Zn additive is added, electrical conductivity is 1.44 × 106 (Ω m)−1. ► The CTE of W–Cu composite are decreased from 9.58 × 10−6 to 8.75 × 10−6 K−1.