Representation of the Viscosity of Molten Alloy as a Function of the Composition and Temperature

Abstract

Although the viscosity of molten metal is very important, the measurement is considerably difficult for high temperature melts. The author's group has developed an oscillating viscometer for high temperature metal. The prediction of the viscosity behavior of the alloys is most useful task because the experimental data acquisition is not easy. In the prediction process, important issue is the composition and temperature dependence. The author has found that the additivity of the logarithmic viscosity was dominant criteria on the composition dependence based on the result of Fe–Si binary melt. Therefore, the logarithmic additivity was adapted to some nickel based super-alloys which were multi component systems. The viscosities of nickel based five binary melts were measured for the representation of the viscosities of super-alloys. The formulation was done by using the separation of variables method. The pre-exponential term and the activation energy were separately approximated as a function of the composition. The results of the approximation successfully represented the viscosities of molten super-alloys.