Surface-modified copper powders with submicrometer tungsten particles for high thermal and electrical conductivity processed via laser powder bed fusion

In recent years, significant progress has been made in the processing of copper (Cu) using laser powder bed fusion for metals (PBF-LB/M). This study investigates a Cu powder mechanically bonded with 3 vol% submicrometer tungsten (W) particles. The copper-tungsten (Cu/W) composite powder provides an alternative to pure Cu for use in PBF-LB/M systems equipped with red light lasers operating at a wavelength of 1070 nm and low laser power below 270 W, while maintaining high thermal and electrical conductivity. The enhanced laser absorptivity of the modified powder enables processing under these conditions. The processed specimens achieve high relative densities of 99.78 % measured optically and 96.46 % measured by the Archimedes method. Thermal conductivity reaches values up to 369.7 W/(mK) measured by laser flash analysis. Electrical conductivity is determined using eddy current testing and yields 51.8 MS/m. In addition, the specific heat capacity and the hardness are measured. The study shows that stable material properties are maintained upon scaling to a standard build plate, and complex components can be reliably produced. To verify the suitability of the material for the PBF-LB/M process, various demonstrator components were successfully manufactured, including cuboids with thin-wall structures and a heat exchanger.