Structural disorder of graphite and kinetics of carbide formation in hypoeutectic Al–Cu/C composite powder

In this study, hypoeutectic Al–Cu/C composite powder was produced via mechanical mixing (for 20 min) and mechanical alloying for 1 and 8 h. The milled for 8 h powder then was annealed at the temperatures below the sintering point (400 and 500 °C) for an hour. The samples were collected after each stage of treatment and studied using by X-ray diffraction (XRD), differential scanning calorimetry (DSC), Raman spectroscopy, nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The results showed the structural disorder of graphite and the kinetics of aluminum carbide (Al 4 C 3 ) formation. Furthermore, the average crystallite sizes in the direction of the graphite plane ( L a ) were also estimated. Transmission electron microscopy (TEM) additionally confirmed presence of the metastable disordered Al 4 Cu 9 phase in the milled for 8 h powder and the carbide after its annealing at the temperatures of 400 °C and above. The effect of defects, which become the most favorable reaction sites between aluminum and carbon, was discussed.