Phases and elemental distributions in SiCp/Al-Cu-Mg composite fabricated by powder metallurgy

SiCp/2009Al composites were fabricated through powder metallurgy and subsequent extrusion. The phases and elemental distributions in the hot pressed and extruded composites were studied. The slight macro-segregation was found in the hot pressed composite billet. The concentrations of Cu and Mg in the bottom of the billet are somewhat higher than those in the top of the billet. The hot pressed composite contains Al, SiC, Al 2Cu, Mg 2Si and a small quantity of Al 7Cu 2Fe and oxide of Mg. After solid solution treatment, Al 2Cu and Mg 2Si dissolved into the matrix and Cu was distributed uniformly in the matrix. However, Mg was still preferentially distributed near the boundaries of the Al particles and in the clusters of SiC. No change of the phases types in the composites was found, however, the extrusion resulted in uniformly distribution of the SiC particles and broke up the oxide shell of the initial Al particles, thus Cu and Mg were distributed homogeneously in the extruded composites after solid solution treatment. © Rright.