Effect of Particle Size Distribution on Sintering Kinetics

4 Effect of Particle Size Distribution on Sintering Kinetics 

As the average particle size in green compact is reduced, the specific surface area increases and the diffusion distance is reduced. Both effects produce higher densification rates. According to the Herring scaling law [22], 

The effect of the particle size distribution on shrinkage rates has been considered previously for the initial stage sintering [46]. The problem was treated for the linear shrinkage of a pair of different size spherical particles in contact. These results were extended to distributions of a few discrete sizes by a weighting of all possible contacts. For a continuous distribution in size, this pairwise interaction can be 

As we have seen before, n and m depend upon the sintering mechanism shown in Tables 16.3 and 16.4. The weighting of some size distribution function fir) gives the shrinkage contribution by particle size as 

The length of the compact or volume of the powder is described according to the contributions by particle size 

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