Fluidity of eutectic grey iron and Al-Si alloys in thin sections

Fluidity of two commercial eutectic alloy liquids, grey cast iron and Al-Si alloy, was investigated. Effects of pouring temperature, modulus of the fluidity channel and incorporation of a filtering system were evaluated. Graphs of fluidity show a linear relationship between fluidity and superheat, as well as fluidity and modulus squared, in both alloys. Comparison of fluidity results indicates that fluidity of Al-12-5%Si alloy is nearly double that of cast iron. The lower fluidity of cast iron liquid may be due to its higher rate of heat loss by radiation. The results of this investigation were compared with those of previous investigators. Although the height of sprue in this work is higher than the common fluidity tests, the results of unfiltered fluidity tests from this work show a similar, but possibly slightly lower, fluidity, probably as a result of additional bulk turbulence in the melt that effectively enhances viscosity. In contrast, when a filter system is employed before the fluidity channel, provided sufficient superheat is available to preheat the filter, the fluidity is increased over that indicated by conventional tests. (C) 2004 W. S. Maney Son Ltd.