Applying glass fluxing combined with thermal cycle, hypercooled solidification was achieved for Ni78.6Si21.4 and Fe83B17 eutectic alloys, thus giving grain refinement and coarsening, respectively, in the as-solidified morphologies. Based on the theoretical analysis in terms of classical nucleation theory (CNT), the above phenomenon can be ascribed to the effect of increased or decreased nucleation rate under hypercooled condition. (C) 2008 Elsevier B.V. All rights reserved.