Effects of induced Cu content on the microstructure and thermal properties of Mo–Cu composites

Mo–Cu composites were fabricated by induced infiltration method. Mo–Cu composites with different Cu contents were prepared by adjusting the induced Cu mass fraction (0～30%). The effects of induced Cu content on the microstructure and properties of the composites were studied. The results show that the content of the induced Cu significantly influences the microstructure of the Mo–Cu composites. When the mass fraction of the induced Cu gradually increases from 0% to 20%, the porosity of the composite is greatly reduced, the distribution of Mo and Cu phases is more uniform, and the single-phase segregation in the microstructure is reduced. However, when the mass fraction of the induced Cu increases to 30%, the microstructure uniformity of the composites becomes worse and the number of pores increases significantly. The electrical conductivity and thermal conductivity of the Mo–Cu composites increase with the increase of the final Cu content in the composites. When the final Cu mass fraction is 40.46%, the relative density of the composite reaches to the peak of 98.1%. Correspondingly, the electrical conductivity and thermal conductivity of the composite are also the highest values, which are 52.69 %IACS and 203.94 W·m⁻¹·K⁻¹, respectively. Unexpectedly, the thermal expansion coefficient of the composites also increases with the increase of the final Cu content. The combination of regulating the induced Cu and exploring suitable infiltration processes is expected to obtain the Mo–Cu composites with improved comprehensive properties.