Measurement of Apparent Viscosity of Ferrous and Non-ferrous Alloys in Liquid/solid Coexisting State-Fe-C, Sn-Pb, Al-Cu and Fe-Cr-Ni-C Alloys

Abstract

Measurement was made on viscosities of partially solidified binary alloys Fe-C (3 and 4%C), Sn-Pb (1.0, 1.5, 5, 15, 25, and 45%Pb), and Al-Cu (4.5 and 10%Cu), and iron-base alloys (Fe-2%Cr-1.5%C, Fe-25%Cr-20%Ni-0.4%C, and Fe-28%Cr-0.4%C). A rotating coaxial cylinder viscometer was used. Solid fraction was calculated for the observed temperatures with the aid of the equation proposed by Scheil. The viscosities were found to depend on the solid fraction, the cooling rate, and the shear rate, as has been reported by FLEMINGS.
When the calculated value of solid fraction was more than 0.6 at the eutectic temperature, the relation between the viscosity and the solid fraction was similar to that for dispersed systems; that is, the viscosity increased remarkably in the range of solid fraction over about 0.5. When the calculated solid fraction at the eutectic temperature was less than 0.6, the viscosity rapidly increased after the temperature of alloy reached the eutectic one.
The viscosity of the iron-base alloys was found to be affected more intensively by the cooling rate than by the shear rate.