Effect of interface bonding and properties of graphite/copper composites by microwave pressure sintering

Abstract

The graphite/copper composites were prepared by different sintering processes. The effects of conventional sintering, microwave sintering, and microwave pressure sintering on the structure and properties of the composites was investigated. The results demonstrate that the microwave electromagnetic field can promote interfacial bonding of graphite and copper matrices, and pressure sintering may further promote interfacial bonding of the copper matrix and grain refinement, thereby improving the overall application performance of the composites. At a sintering temperature of 950 ℃, a holding time of 1 h, and a graphite volume fraction of 50 vol%, the physical and mechanical properties of the composites prepared by microwave pressure sintering were optimal when the pressure was 350 kPa. The internal thermal conductivity of the cross plane was 681.0 (W·m−1·K−1), the tensile strength was 32.57 MPa, and the elongation at break was 18.46%. It is proved that microwave pressure sintering is beneficial to improve the comprehensive properties of composites, and provides a new research idea for the preparation of graphite/copper composites with high thermal conductivity.