Effects

1.7.2 Effects of Gravity
The relatively low effective viscosity of powder compacts containing a liquid phase leads to ready creep, and the weight of the sample itself can cause significant deformation. Additional problems are the possibility of liquid redistribution. This is most likely for liquids such as molten metals, or when a significant amount of liquid is present (e.g. more than 5 vol. %) resulting in possible particle settling or liquid drainage.
1.7.3 Grain Boundary Films
Initially, when there is a significant amount of liquid between the grains, the thickness of the grain boundary is kinetically determined. The thinning rate, a consequence of capillary viscous flow, of the liquid film at a grain boundary of fixed cross-section.
1.7.4 Effective Stress
Considering a cross-section that runs through the particle-particle contacts, the particle network, or skeleton,
1.7.5 Role of the Wetting Angle
The wetting angle, ?, for the liquid/solid/vapor system depends on the various interracial energies, and is usually referred to a droplet of liquid on a flat solid surface. While this does not represent the full equilibrium,1.7.6 Relative Amount of Liquid Phase
The distribution of the liquid phase depends on the dihedral angles and the relative amount of liquid phase, as well as on the porosity. For contact angles larger than zero, it becomes possible to have the liquid phase actually produce repulsive forces rather than attractive forces between the particles. For such a case, further densification can only proceed by grain growth.