The additive manufacturing of copper with conventional LPBF systems is challenging due to the high reflectivity of copper for wavelengths of standard infrared lasers and other characteristic properties like the high thermal conductivity. Green laser systems with a wavelength of 532nm pose an opportunity to reduce the necessary power of the laser systems and the number of defects while increasing the relative density. This study presents the results of a process development for a 532nm laser system for the LPBF process. Dimensionless indicators are used to analytically describe the probability of lack-of-fusion defects and investigate process parameters to achieve dense parts. The produced specimens are analyzed regarding their relative density as well as their hardness, tensile properties and electrical conductivity. It is found that dimensionless process indicators are generally suitable for an analytical approach in process development, but the adaptation to different processes results in the need for adjustment. A lower variation is found for the used dimensionless number compared to the volumetric energy density. The produced parts show a relative density of up to 99.5 % or more and mechanical and electrical properties, which are comparable to conventionally manufactured copper. A high relative density is achieved with a laser power of $$192 W$$ 192 W , a laser scan speed of 400 mm/s and a hatch distance of $$50 \mu m$$ 50 μ m .

Additive manufacturing (AM) of copper is subject to dynamic development regarding available processes and the quality of produced parts. While challenging, AM processes for copper provide parts with a quality comparable to other metallic material groups like steels. The reasons for the lower prevalence of additive manufacturing of copper components in industrial applications are currently not sufficiently researched, especially in light of the significant progress made in the maturity of this technology. A survey is used to investigate the assessments of protagonists in the field of copper AM. The needs of current and potential users of copper AM are analyzed and outlined. This study reveals that the most relevant technical limitation for users is the reduced surface quality of parts, while overall processes need to become less costly and more reliable to find broader use. Answers given hint to a higher degree of automation, the possibility of multi-material processing, and the upscaling of machine and part sizes as relevant future trends in the copper AM sector.

Digital twins are increasingly being used to visualize, analyze, or control physical processes and systems. Implementation currently poses challenges for users due to the cross-domain complexity of digital twins. In this study, the authors utilize a self-developed method to support the implementation of a digital twin (DT) for a powder bed fusion additive manufacturing system (PBF-LB/M) for copper components, utilizing a green laser. The study highlights the support offered by the developed approach and the implications of using DTs for PBF of copper. The DT focuses in particular on monitoring maintenance requirements, assisting in the selection of correct process parameters, and alerting plant operators in the event of problems. In addition, a process model focused on lack of fusion is implemented, based on earlier studies. In the human–machine system, DTs thus represent a further building block towards an improved process stability in PBF-LB/M of copper, and the method used lowers the barrier to entry for widespread use of DTs.

Additive manufacturing (AM) is becoming increasingly important for processing challenging copper-based functional materials. AM offers the promise of combining outstanding material properties with new design opportunities and enhanced functionalities. While pure copper offers high thermal and electrical conductivity, its mechanical properties are insufficient for applications requiring high strength. Therefore, precipitation hardening alloys like CuNiSiCr can be utilized to achieve high functional and mechanical performance simultaneously. In the study presented, the copper material CuNiSiCr was processed using a 532 nm laser via powder bed fusion for metals (PBF-LB/M). The investigation of a suitable high-density process window yielded a relative density of 99.89% ± 0.03%. Build orientation effects on the tensile properties were investigated, with median ultimate tensile strengths decreasing to 235 MPa (90°) from 262 MPa (0°). The findings of this study indicate that the advantages of green laser PBF-LB/M persist for the used CuNiSiCr alloy, with comparable relative density achieved at a lower energy input.