Sintering local driving force

As mentioned earlier, the global driving force operating during sintering is the reduction in surface energy, which manifests itself locally as curvature... 

According to Greskovich and Rosolovski [372] and Prochazka [373], the specific surface area during the initial state of sintering is mainly consumed by a coarsening of the particles and pores, which in turn reduces the driving force for densification (local chemical potential). Densification comes to an end before pore closure is obtained. This so-called terminated density has been observed for pure boron carbide, SiC and silicon nitride, when no sintering aids are present. 

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