## Publica

Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten. # Constitutive equations for the mechanical behavior of powder compacts during sintering

**Abstract**

Constitutive equations for the mechanical behaviour of porous solids during sintering are derived for equilibrium configurations of open and closed prosity. In a first step equilibrium surfaces are determined numerically for various periodic arrangements of grains. This yelds contact areas and sintering forces as a function of the relative density and of the dihedral angle. The transition to closed porosity is part of the result. In the second step, densification and creep is investigated by analyzing grain boundary diffusion in the contact areas. The resulting bulk and viscosities depend on the grain size, for which an evolution equation is given. The completed equations for densification and grain coarsening are solved numerically, and the conditions for pore/boundary separation are explored.