To produce aluminum-matrix composite reinforced by graphite particles, mixing of pure aluminum and graphite powders by a new method, called homogenization in liquid phase, was used. The graphite content was chosen from zero to 4.5wt.% in this study. Composite samples were produced using the mixed powder by two ways: spark plasma sintering (SPS) and cold-press sintering (CPS) under different pressure, temperature and time. The specimen microstructures were investigated by optical microscopy and scanning electron microscopy (SEM). To evaluate the mechanical properties of samples, compression and hardness tests were performed. According to the results, homogenization in liquid phase method caused significant improvement in distribution of graphite particles in the matrix and the addition of 3wt.% graphite in the matrix was gained. Improved mechanical properties were obtained at the optimum graphite percent. According to the results, the compressive strength of the composite, obtained from this mixing process and cold-press and sintering, was increased at least 43.2% compared to the pure aluminum. Moreover, with changing SPS parameters such as pressure, the strength of Al- Gr composite to about 104.8%, compared to the pure aluminum. In addition, it was shown that the specimen with the optimum graphite content (3 wt.%) has compressive strength up to 138.7% and hardness up to 69.6% relative to pure aluminum specimen.

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