Fundamental Aspects of Sintering

Olevsky EA, Bradbury WL, Haines CD, Martin DG, Kapoor D (2012) Fundamental aspects of spark plasma sintering I. Experimental analysis of scalability. J Am Ceram Soc 95 2406-2413... 

Some fundamental aspects of equilibrium and non-equilibrium phase equilibria have been discussed, along with the major factors that influence reactivity in the solid state. These topics are of crucial importance in ceramic technology and must be addressed in spite of their complexity and the considerable time, effort, and expense required to perform meaningful experiments. They impact on the entire range or relevant science and engineering from synthesis to sintering and final determination of the material s properties. 

So far, Coble s model has been a standard for interpreting and predicting the densification at final stage sintering. In Coble s model, however, a fundamental aspect is not taken into account, namely, the grain boundary as the atom source for densification. In addition, it is hard to accept Coble s flux equation (Eq. (5.7) under riconstant material flux from grain boundaries to the surface of a pore irrespective of pore size. 

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