Effect of interfacial-active elements addition on the incorporation of micron-sized SiC particles in molten pure aluminum

Ceramic particles generally have poor wettability by liquid metal, leading to a major drawback in fabrication of cast metal matrix composites (MMCs). In this work, the effect of 1 wt. % of Ca, Mg, Si, Ti, Zn and Zr interfacial-active alloying elements was studied on the incorporation of micron-sized SiC particles into the molten pure aluminum using the vortex casting method at 680 °C. The results indicated that Ti, Zr, Zn and Si were not positively effective in improving particulate incorporation, while Ca and especially Mg were very efficient at increasing the incorporation of ceramic particles into the molten Al. Also, it was revealed that Al3Ti, and Al3Zr intermetallic phases were formed for samples containing Ti and Zr, making hybrid MMCs with a higher amount of hardness. Finally, it was found that a reaction layer between Al and SiC particles was formed at the Al/SiC interface for all of the samples, expect for the ones containing Si and Ti, indicating that for most of the samples at 680 °C an exothermic reaction took place between the Al and SiC particles.