Dispersion of graphite, Ceria, and nanohybrid Ceria-graphite in the 6063 aluminum alloy through powder metallurgy

The effect of graphite, CeO2 and nanohybrid CeO2-graphite on an Al–Mg–Si system (6063 alloys) was studied in this paper. Such alloy was reinforced using mechanical milling, followed by a conventional sintering process. Studies for structure, microstructure, and mechanical properties were carried out through X-ray diffraction, electron microscopy, and compression and Vickers microhardness testing. Results showed that the milling process enables homogeneous dispersion of the different reinforcement materials in the Al–Mg–Si matrix. The best performance, concerning reinforcement capacity and microhardness, was obtained with samples reinforced with graphite. The mechanisms involved in enhancing the mechanical properties were active and latent. The first includes grain-size refinement and strengthening by dispersion of a second phase, and the second is related to thermal mismatch.