Influence of interfacial reaction on the fluidity of A356 Al –SiCр Composites: A theoretical approach

Abstract

Fluidity behavior of the A356 Al-SiCp composites has been theoretically predicted using the Flemings model after incorporating (I) the solidification behavior of the alloy; (2) the decrease in flow velocity due to surface tension and friction loses; and (3) the increase in viscosity of composite slurries due to size, shape, and volume fraction of the reinforcement. It is observed that the fluidity values of A356 Al alloy and A356 Al-10 vol pct SiCp composite predicted by the modified Flemings model are in good agreement with the experimental values reported in the literature. On the other hand, the theoretically calculated fluidity length of A356 Al-15 and 20 vol pct SiCp composites using the modified Flemings model agrees well with the experimental results only up to 750°C and 710°C, respectively. However, above these respective temperatures, the experimental spiral length decreases with pouring temperature, whereas the theoretically calculated spiral length increases linearly as a function of pouring temperature. Incorporation of experimentally calculated interfacial reaction terms in the modified Fleming model makes the predicted and experimental values of fluidity of A356 Al-15 and 20 vol pct SiCp composites closer in the entire temperature range. Thus, the high dependence of the fluidity of A356 Al-SiCp composites on the morphology of the interfacial reaction product is demonstrated.