Enhanced electrical and mechanical properties of additively manufactured pure copper with green laser

Abstract

The effort to improve the additive manufacturing (AM) of copper, which is essential in various industrial sectors, has led to the exploration of green laser powder bed fusion (GL-PBF). By using a high-energy green laser, we overcome the challenges posed by the high reflectivity of copper, which has previously hindered achieving the desired component densities and functionalities through AM. This study uncovers the key role of GL-PBF process parameters on the densification, microstructure, surface roughness, mechanical properties, and electrical conductivity of pure copper parts. Our findings demonstrate that optimizing GL-PBF parameters can achieve copper components with over 99.9 % relative density and 98 % international annealed copper standard (IACS) electrical conductivity. The combination of comprehensive experiments and finite element modeling also reveals how the critical role of defect morphology in affecting electrical conductivity. This work contributes to the broader application of AM technologies, especially for high-reflectivity metals, and also provides new insights into how these defects affect conductivity and should be controlled during the AM process.