Abstract
Laser additive manufacturing of pure copper (Cu) with complex geometries opens vast opportunities for the development of functional devices in microelectronics and telecommunication. However, laser additive manufacturing of high-resolution pure Cu remains a challenge. Here we report a facile oxide-dispersion-strengthening (ODS) strategy that enables additive manufacturing of Cu with sub-100 μm (~70 μm) resolution by laser powder-bed fusion. This ODS strategy starts with oxygen-assisted gas atomisation to introduce ultrafine Cu(2)O nanoparticles into the pure Cu powder feedstock. These nanoscale dispersoids not only improve the laser absorptivity and the viscosity of the melt but also promote dynamic wetting behaviour. The ODS Cu exhibits a remarkable yield strength of ~450 MPa and a large uniform elongation of ~12%, while preserving a high electrical conductivity. As an example, we printed an ODS Cu micro-architected terahertz antenna, which demonstrates a 2.5-fold improvement in signal intensity compared with traditional 3D-printed pure Cu antennas.