Abstract:The laser powder bed fusion (L-PBF) process for manufacturing copper typically exhibits poor strength-ductility coordination； the addition of enhancers is usually an effective way to improve it. However, there is relatively limited research on Cu composites. To explore the impact of enhancements on Cu, we used a Cu-CNTs mixed powder as the base and applied the L-PBF technology to produce a Cu-CNTs composite. We studied its forming performance, microstructure, and mechanical properties, as well as its conductive and thermal properties. The resulting composite has a high relative density of consolidated Cu-CNTs material. The addition of CNTs results in non-uniform microstructure with equiaxed grains at the edges of the melt pool and columnar grains at the center. Compared to pure copper, the overall mechanical properties of the composite are improved (tensile strength increased by 52.8%, elongation increased by 115.9%), and the electrical and thermal properties are also enhanced (thermal conductivity increased by 10.8%, electrical conductivity increased by 12.7%). The results indicate that the addition of CNTs can increase the tensile strength and elongation, as well as the electrical and thermal properties of copper. Therefore, this material provides an efficient pathway for designing more efficient heat sink structures.