A generalized viscoelastic Maxwell model for semisolid thixotropic alloys.

More advanced investigation of any thixoforming process gives evidence that apart from the typical thixotropy also some viscoelastic features can be observed, particularly at high volumetric solid fraction. From the micrographic analysis one can conclude that the elastic properties have the origin in the solid globules, which are deformed in a flow process. In any sudden increase of deformation rate one can observe characteristic stress overshoot proving the elastic properties. The globules and their agglomerates after elastic deformation slide along each other (the drag flow) and on the occasion break the physical bonds within the agglomerates giving rise to the thixotropy phenomenon resulting in the apparent viscosity decrease.