Production of silicon carbide Al 2124 alloy functionally graded materials by mechanical powder metallurgy technique

Abstract

A mechanical powder metallurgy process involving a vibration stage before cold and hot compaction has been developed to manufacture functionally graded materials (FGMs). The microstructure and mechanical properties of SiC_p/Al 2124 FGMs produced by this process have been studied. It was found that the vibration stage modified the SiC distribution from a layered structure to a smoothly changing SiC content with position in the sample. The vibration process also improved local homogeneity by breaking up the coarse SiC agglomerates which tended to form in high SiC content regions of the FGMs. Multilayered FGMs exhibited superior toughness to their metal matrix composite counterparts and there were indications that toughness was further enhanced in the continuous SiC gradient FGMs produced by the vibration stage.