Viscosity of aluminum-based hypereutectic alloys doped with iron

We investigated the temperature dependences of the kinematic viscosity of liquid $\mathrm{Al}$–$\mathrm{Fe}$ alloys with an iron content from $3.5$ to $10\%$ (atomic). We discovered a bifurcation of the viscosity polytherms obtained upon heating and subsequent cooling. We show that the value increase observed in the viscosity polytherm at melt heating near the liquidus temperature is caused by $\mathrm{Al}_3\mathrm{Fe}$ crystal sedimentation upon its passing the two-phase zone and by their subsequent melting.