High-strength and high-conductivity pure copper by powder bed fusion with a medium-power infrared laser

• A medium-power infrared laser achieves dense pure copper by powder bed fusion. • The relative density of additively manufactured copper reaches 99.8 %. • The as-built microstructure contains fine grains and high-density twin boundaries. • The fabricated pure copper exhibits high strength and high electrical conductivity. Additive manufacturing (AM) enables unparalleled design flexibility and direct fabrication of intricate structures, thereby minimizing assembly complexity, shortening production time, and enhancing operational efficiency. Pure Cu is highly desirable for energy and electronic applications due to its excellent electrical and thermal conductivity. However, its high reflectivity and thermal conductivity present significant challenges in achieving high density via AM. In this study, we demonstrate the fabrication of high-density, high-strength, and high-conductivity pure Cu using a commercial laser powder bed fusion (LPBF) system equipped with a 400 W, 1060 nm infrared laser. Through the employment of fine Cu powder (5–25 μm), thin layer thickness (20 μm), and process optimization, we have achieved a remarkable relative density of 99.8 % and a fine-grained microstructure. The as-printed pure Cu exhibits high yield strength of 236 MPa and ultimate tensile strength of 323 MPa, surpassing conventionally manufactured pure Cu, and demonstrates an outstanding electrical conductivity of 97.3 % international annealed copper standard (IACS) without post-processing heat treatment. Our work presents an efficient strategy for fabricating high-performance pure Cu components using commonly available medium-power LPBF systems, broadening the potential of AM in sustainable manufacturing and next-generation energy devices.