Solidification Observations of Dendritic Cast Al Alloys Reinforced with TiC Particles

TiC particulate composites in the range of 3 to 5 vol.% were prepared by diluting Al/20 vol.% TiC composite in Al7Si, Al20Cu, and Al20CuNi alloy matrices. TiC particle distribution consists of isolated particles located both at the primary α-dendrites and the areas of the lastly solidified liquid and particle clusters located at the grain boundaries. Particle-solidification front interactions were responsible for the final particle location and the mechanisms of such behavior were analyzed. The solidified microstructure consists of primary, eutectic, and other intermetallic phases, with the latter being associated with the presence of TiC particles.