The Effect of Grain Refining of Primary Aluminum on the Fluidity of Al-Si Casting Alloys

Abstract

Aluminium alloys, and particularly aluminium silicon alloys, have found extensive use in engineering applications. Improving the mechanical properties of the cast alloys is important. One of the means of achieving this is by grain refinement using grain refiners. The grain refiners affect the fluidity, and consequently solidification, of the alloys. In this study, the fluidity of nineteen Al-Si alloys made with silicon of 99.999% purity and aluminum of 99.999% purity were investigated using a straight channels mold. The casting modulus of the channels varied between 0.2 mm and 2.9 mm. Using the same quality of materials, Ti-B-Al was added to alloys with silicon content between 0% and 16%. In the 0.91 mm modulus channel a decrease varying from 50% to 2% was observed in the solid solution alloys while in the hypo-eutectic alloys fluidity decreased by 16% to 45%. However, in the hyper-eutectic alloys, fluidity increased by 8% to 18%.