Effects of CNTs Addition on Microstructure and Properties of Pure Copper Prepared by LPBF

Abstract:

Copper manufactured by laser powder bed fusion (LPBF) process typically exhibits poor strength-ductility coordination, and the addition of strengthening phases is an effective way to address this issue. To explore the effects of strengthening phases on Cu, Cu-carbon nanotubes (CNTs) composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix. The formability, microstructure, mechanical properties, electrical conductivity, and thermal properties were studied. The result shows that the prepared composites have high relative density. The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center. Compared with pure copper, the overall mechanical properties of the composite are improved: tensile strength increases by 52.8% and elongation increases by 146.4%; the electrical and thermal properties are also enhanced: thermal conductivity increases by 10.8% and electrical conductivity increases by 12.7%.