The powder metallurgy (P/M) processed 2009 and 2124 Al composites reinforced with SiC particulates were studied by focusing on the effect of consolidation temperature on the microstructural and mechanical Properties. The mechanical properties such as tensile properties and microhardness of the second phases were analysed in relation to the microstructures observed by a SEM and an optical microscope. The in situ fracture process study using SEM showed that the grain refinement and the removal of manganese-containing particles often observed in the 2124 Al- composites were important for the improvement of the mechanical properties. This study offers an optimum consolidation temperature for the control of the manganese-containing particles in the 2124 Al- composites that yields mechanical properties higher than those of the 2009 Al- composites.