Formation of the microstructure during sintering

Consequently, both the geometry and the density of sources and sinks for the sintering reaction are continually changing. When we view the entire sintering process in all its complexity, we can readily understand that a complete quantitative treatment is virtually impossible [17]. Therefore, in the following, we shall simply discuss the concepts and sketch out the equations necessary for a quantitative analysis. 

In order to simplify the discussion, let us consider a model in which cylindrical particles of equal radius are piled up in a close-packed array. Furthermore, we distinguish three stages 

If X is the width of the contact area, then the rate law over a certain time interval will be of the form x = kt, where n 1. 

The second stage may be defined as follows Grain boundaries emanate from every pore to the neighbouring pores. Grain growth has not yet occurred (see Fig. 9-2). 

This flux is responsible for the decrease in the volume of the pore. If is the volume of the pore per unit length, then  

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