Constitutive Behavior of Semi-Solid Metal Alloy Slurries

The constitutive flow behavior of semi-solid metal alloy slurries has been modeled using an internal variable framework. The formulation represents the primary flow response of these materials: history dependence (thixotropy), steady state shear rate thinning(pseudoplasticity) and constant internal structure shear rate thickening (dilatancy). The flow response at any given structure has been decoupled from structure-dependent response in carefully controlled rapid transient experiments done on a computer-controlled, high temperature, Couette geometry rheometer. The data for Sn-15wt% Pb correlates well with the model.