添加CNTs对激光粉末床熔融纯铜的微观结构和性能的影响

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

摘要:

激光粉末床熔融（LPBF）工艺制造铜通常表现出较差的强度-塑性配合，添加增强相是改善这种配合的有效方法。为了探究增强相对Cu的影响，以Cu-碳纳米（CNTs）混合粉末为基体，采用LPBF技术制备了Cu-CNTs复合材料，研究了其成形性能、微观结构、力学性能、导电性能和热性能。结果表明，所制备的复合材料具有较高的相对密度。CNTs的加入导致了熔池边缘等轴晶粒和中心柱状晶粒的不均匀。与纯铜相比，复合材料的整体力学性能得到改善（抗拉伸强度提高52.8%，伸长率提高146.4%），导电性能和热性能也得到提高（导热系数提高10.8%，电导率提高12.7%）。

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%.