2006 Volume 78 Issue 1 Pages 3-8
One-dimensional solidification analyses of casting based on the relationship between the degree of undercooling and the increasing rate of solid fraction were carried out for cast iron and aluminum casting. Analytical solutions of the cooling curve showed that the degree of undercooling during solidification increased, with decreasing thickness of plate-type casting and the coefficient of undercooling for the increasing rate of solid fraction. By taking into account undercooling, it is possible to simulate the pattern of mushy-type solidification in which the surface and central part of the casting solidify almost at the same time, even for alloys with small solidification range. The difference in solidification time between the surface and center of casting for aluminum casting was smaller than that for cast iron. The solidification characteristics of aluminum casting were also more remarkable than those of cast iron. In cylindrical and spherical casting, the degree of undercooling near the completely solidified point was larger than that during solidification. The acceleration of the velocity of solid-liquid interface near the center of the casting was observed particularly in aluminum casting.
