Interface Observation of Aluminum-Coated Carbon Nanofibers Prepared by in Situ Chemical Vapor Deposition

Abstract

The compatibility of carbon nanofibers (CNFs) with aluminum is important for the fabrication of CNF-reinforced aluminum matrix composites with superior mechanical and thermal properties. In this study, aluminum was deposited on CNFs by in situ chemical vapor deposition (CVD) utilizing I2 for the transportation of aluminum atoms. The microstructure of the aluminum-coated CNFs and the crystal structure of the aluminum coating layers were studied. When aluminum powder with ∼3 μm diameter particles, CNFs, and I2 powder were mixed in the molar ratio 1:1:0.1 and annealed at 500 °C for 48 h, the coating layer formed was polycrystalline and exhibited preferential orientation of the (002) and (111) aluminum planes; the grain size of aluminum in the coated layer was ∼5 nm, the interface structure was governed by the CNF surface structure, and an amorphous region or aluminum oxycarbide (Al4O4C or Al2OC) was formed at the interface. When larger 106–180 μm particles of aluminum were used, a larger amount of I2 was req...