Effect of microwave sintering temperature on microstructures and properties of CNTs/Cu composites

Carbon nanotubes reinforced copper-matrix (CNTs/Cu) composites were prepared by the combination of liquid phase method, microwave sintering, and rolling technology. The effects of sintering temperature on micromorphology, mechanical properties, and physical properties of CNTs/Cu composites were investigated. The results show that, 0.5% CNTs/Cu composite powders (mass fraction) are prepared by liquid phase method with the diameter of 200~500 nm, the carbon nanotubes are uniformly dispersed in copper particles, forming a good bonding interface with cooper. The relative density, hardness, and electrical conductivity of CNTs/Cu composites first increase and then decrease with the increase of sintering temperature. The optimum properties of 0.5% CNTs/Cu composites are obtained when the sintering temperature is 1000℃, which show the less pores and uniform distribution, the relative density reaches 95.79%, the hardness is HV 80.9, and the electrical conductivity is 81.8% IACS. Subsequent rolling process enables the better performance of sintered composites which shows the tensile strength of 218 MPa and the elongation of 37.75%. Thus, it can be seen that the microwave sintering technology is an ideal method for the preparation of high-performance CNTs/Cu composites.