Remarkable improvement of wettability of Cu-coated carbon nanotubes by molten aluminum.

The wettability plays a decisive role in the mechanical performances of the aluminum matrix composites reinforced with carbon nanotubes (CNTs). In this paper, novel Cu nanoparticles-coated CNTs (Cu@CNTs) were prepared successfully by the liquid phase reduction method to enhance the wettability of CNTs in aluminum melt. The microstructure, contact angle, and interfacial structure of aluminum liquid on Cu@CNTs substrate at high temperature were investigated by scanning electron microscopy (SEM) and sessile drop method in detail. By incorporating Cu nanoparticles on the surface of CNTs, the contact angle was reduced from 133° to 91°, indicating a significant improvement in the wettability of CNTs in aluminum melt. The atomic diffusion of Cu and Al elements leads to a remarkable improvement of wettability for Al-Cu@CNTs model. The coating of CNTs provides a new insight for strong wettability in high-performance aluminum matrix composites. [Display omitted] • Cu-coated CNTs were successfully synthesized via compound reduction method with ethylene glycol and N 2 H 4· H 2 O reductant. • With the contact angle reducing from 133° to 91°, the wettability of CNTs to aluminum melt was improved by coating Cu nanoparticles. • The better wettability of Cu@CNTs to aluminum melt attributes to small amount of element Al can react with Cu on Al-Cu@CNTs interface to form AlCu or Al 2 Cu, which can greatly enhance the bonding strength of composites. [ABSTRACT FROM AUTHOR]