Biopolymer-Assisted Manufacturing of Aluminum–Copper Nanoparticle Composites with Enhanced Sinterability

Sintering is an essential step to obtain bulk components from aluminum powders, which enables powder metallurgy-based fabrication methods such as additive manufacturing technologies. Copper (Cu) can form alloys with aluminum (Al), and the introduction of Cu particles can be used to enhance the sintering behavior of Al alloys. Good dispersion of Cu particles is critical in such approaches, which, however, may be difficult to achieve. In this study, Cu nanoparticles (NPs) were synthesized and attached to the surface of Al powder particles with the assistance of a polydopamine (PDA) coating. This composite powder showed enhanced sintering behavior, which may be attributed to the Al–Cu alloy phase(s) formed at grain boundaries. The improved electrical and mechanical properties of the sintered material demonstrate that this combined Cu NP deposition and PDA coating approach is a good candidate method for the manufacture of Al powders with enhanced sinterability.