| Abstract Scope |
The creation of 3D high-resolution copper (Cu) devices with high mechanical strength and electrical conductivity is essential for numerous applications, including telecommunications, electronics, and thermal management, etc. Recent advancements in laser additive manufacturing (AM) have facilitated the near-net-shaping of Cu components featuring intricate geometries. However, a significant challenge associated with the laser AM of Cu is the difficulty in controlling the defects, such as lack-of-fusion or keyhole pores, which stem from Cu 's intrinsic physical properties - namely, its high infrared laser reflectivity and thermal conductivity that impede effective dense solidification. This study introduces a novel oxide-dispersion-strengthening (ODS) method aimed at simultaneously increasing the laser absorptivity of Cu powder feedstock and improving the stability and wettability of the Cu melt. This technique significantly improves printing resolution and material properties for AMed Cu components. Our ODS approach demonstrates considerable advantages in generating high-strength Cu, enhancing printing resolution in laser powder bed fusion. Unlike conventional ODS techniques that manually deposit external oxide particles onto feedstock surfaces, we incorporate oxide nanoparticles into Cu powder feedstock by controlling oxygen concentrations during gas atomization. The oxygen-assisted gas atomization (OAGA) method ensures uniform distribution of oxide nanoparticles throughout the powders, from the core to the surface. Utilizing these OAGA-produced powder feedstocks, our 3D-printed ODS Cu components exhibit remarkable mechanical properties, attaining a strength of 450 MPa and a high printing resolution of approximately 70 μm, while maintaining superior conductivity exceeding 80% of the International Annealed Copper Standard (IACS). The proposed ODS approach presents many opportunities for advancing next-generation micro-architected Cu devices in various applications via laser AM. The implementation of ODS effectively resolves the trade-off between material properties and printing resolution typically encountered in conventional AM of pure Cu. |