Characterization of aluminum-carbon composites obtained via mechanical activation of aluminum and carbon nanotubes

The relaxation of structural defects of aluminum-multiwall carbon nanotubes (MWCNT) composite materials obtained via mechanical activation is studied in situ by X-ray diffraction using synchrotron radiation. Mechanically activated Al-MWCNT mixtures are annealed at temperatures of up to 600°C in an inert gas flow and X-ray diffraction patterns are simultaneously registered with a position-sensitive X-ray detector. It is demonstrated that mechanically activated samples of pure Al and composites with large-diameter MWCNTs (～20 nm) begin to experience the relaxation of defects accumulated during mechanical activation at temperatures as low as 100–150°C, while samples with small-diameter MWCNTs (～10 nm) exhibit thermal stability of structural defects up to 500°C.