Liquid-phase sintering capillary forces

R.B. Heady and J.W. Cahn. An analysis of capillary force in liquid-phase sintering of spherical particles. Metall. Trans., 1(1) 185—189, 1970. 

Eremenko, V. N., Naidich, Y. V. and Lavrinenko, I. A., Modelling of capillary forces acting during sintering in the presence of a liquid phase, in Liquid Phase Sintering, Consultants Bureau, New York, 55-65, 1970. 

It is often assumed in the theoretical analysis of liquid-phase sintering that the composition and structure of the grain boundary liquid phase is constant. However, this is not always the case. A wetting liquid layer, as described earlier, leads to the development of a compressive capillary force, which is equivalent to placing the system under a fairly large hydrostatic compression. The evolution of the intergranular liquid layer under the influence of the capillary force as well as other forces has been the subject of recent investigation. 

Densification results from particle rearrangement under the influence of capillary forces and the filling of pores by the liquid phase. This process is very rapid, and if during the early stages of sintering, the liquid flows and completely fills the finer pores between the particles, 100 percent densification can result almost instantaneously. 

The topic of capillary forces was introduced in Section 13.6. This topic is extremely important in sintering when there is a liquid phase present. The overall plan of our discussion is shown in Figure 24.4. 

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