Fabrication of metal coated carbon nanotubes by electroless deposition for improved wettability with molten aluminum

Ni–P alloy coated and Au/Ni–P alloy double-coated multiwalled carbon nanotubes (MWCNTs) were fabricated using electroless plating. Three types of electroless Ni–P alloy plating baths were prepared to coat the MWCNTs with Ni–P alloy films of varying phosphorus content. Electroless gold coating of the Ni–P alloy coated MWCNTs was also carried out using a non-cyanide bath. The microstructures of the coatings on the MWCNTs were examined by scanning electron microscopy and X-ray diffraction. The wettability of the metal-coated MWCNTs with molten aluminum was also evaluated. MWCNTs coated with Ni–P alloy films containing 9–25 at.% phosphorus content were fabricated by electroless deposition. Electroless gold deposition on the Ni–P alloy coated MWCNTs to form Au/Ni–P alloy double-coated MWCNTs was also possible. The wettability of the metal-coated MWCNTs with molten aluminum was significantly improved compared to that of non-coated MWCNTs. The coating metals of the MWCNTs dissolved into the molten aluminum, resulting in good wettability between the MWCNTs and molten aluminum and dispersion of the resulting bare MWCNTs in the aluminum matrix. The dissolved coating metals formed stable compounds with molten aluminum.