Studies on eutectic Al–Si alloy–flyash composites

Abstract

In this investigation, an attempt was made to study the influence of melt treatments like grain refinement and modification on the mechanical properties of cenospheres of flyash–LM6 composites. Stir casting route was employed to disperse the flyash (1–15 wt‐%) in the LM6 alloy matrix. For each percentage of flyash, melts were subjected to grain refinement, modification or combined grain refinement and modification. The results reveal that castings subjected to melt treatments showed increased hardness, ultimate tensile strength and elongation compared with untreated Al–Si base alloy up to 10% flyash. Addition of flyash beyond 10% resulted in decreases in hardness and ultimate tensile strength. Percentage elongation showed a decreasing trend for all the cases studied. Nevertheless, in all the cases studied, mechanical properties were higher than that of the Al–Si base alloy. Among all the composites, the best results were obtained with 10% flyash subjected to modification alone.