Manufacturing of complex diamond-based composite structures via laser powder-bed fusion

Manufacturing complex metal matrix composite (MMC) structures by laser powder-bed fusion (LPBF) could unleash their full potential but is difficult due to the presence of reinforcement. Unmelted particles negatively affect the pool dynamics, cause critical spatter ejections, and form printing defects. In this work, by taking copper (Cu) / diamond (D) composite as an example for its prospective thermal management applications and machinability limitations; we discovered that adding steps to LPBF enables the fabrication of high-quality materials and structures. We demonstrated that adding a recoating step improves the composite quality compared to structures manufactured by conventional LPBF. Adding a remelting step enabled further improvement by limiting the generation of spatter and printing defects, leading to 3D laser print dense (97%), highly thermally conductive (349 W/m K) and complex Cu/5 vol% D structures. Therefore, pursuing research into nonconventional LPBF could open new avenues for manufacturing MMCs.