Effect of alloying element Zr on the microstructure and properties of graphite flake/Cu composites fabricated by vacuum hot pressing

Graphite flake/Cu composites with Zr element introduced into the matrix were successfully fabricated by vacuum hot pressing. The influence of Zr addition on the phase composition, microstructure and properties were investigated. The results indicate that the bending strength in X-Y plane gradually rises with the Zr content increasing from 0 to 2.0 wt%, nearly doubled from 50 MPa to 95 MPa. The thermal conductivity in X-Y plane initially increases and then decreases, yielding a maximum of 640 W m−1 K−1 at 1.0 wt% Zr. This improvement is ascribed to the formation of carbide interfacial layer at the graphite flake/Cu interface. Due to the simple preparation process and excellent thermal conductivity, the graphite flake/Cu composites with moderate Zr addition can be a highly promising candidate for thermal management materials.