Evaluation of crystal multiplication at mold wall during solidification of casting

Abstract

The effect of crystal multiplication at the mold wall during casting process, so-called "Big Bang" phenomenon, on the macrostructure of Al-Si alloy was examined, Conventional casting experiments were carried out and the degree of the crystal multiplication at the mold wall was evaluated by simulating the macrostructures similar to the experimentally observed ones using a cellular automaton method. The degree of the crystal multiplication decreased with increase In superheat of the molten alloy at the pouring, The reason of this can be attributed to the remelting of suspended crystals formed due to the crystal multiplication by superheated melt. © 2008 ISIJ.