Unidirectional Solidification of (Al-Si) Eutectic Alloy

Abstract

This paper provides an overview of the mechanical properties of reinforced Al-12%Si alloy by uni-directional of the eutectic phases in specific direction. A special solidification unit have been designed and manufactured to ensure the correct orientation of growing eutectic phase. Two types of insulation materials have been used to isolate the carbon steel mold of solidification unit, (dry sand and glass wool). The second type insulator found to be favorable in augmenting the growth and uni-direction of eutectic phase with the conditions of cold water flow through the unit. The produced microstructure consists of little elongated α-phase with a noticeable correct orientation of the growing discontinuous eutectic phase in the direction of heat sink. Hardness, tension, compression and impact properties have improved in comparison with the samples of free mold isolation case (i.e. free solidification). These results reflect directly the effect of uni-directional growth of eutectic phase in the reinforcement process of the investigated alloy as an in situ-composite material.