where J is the atomic flux, A is the bond area over which the new mass is distributed, and His the volume of a single atom or molecule. The change in curvature with position gives a chemical gradient that directs mass flow into the sinter bond between the particles. The deposited or removed atoms change the neck size and shape. In turn the new shape and curvature gradient influence the flux. High temperatures promote faster mass transport and thereby contribute to faster dv dt


neck growth. Many concurrent deposition processes react simultaneously to the same driving force. Consequently, accurate calculations of sintering rates require numerical techniques.

Sintering models with simplified forms are available that provide an estimate of the relative rate of neck growth from any transport mechanism. These result in the following initial stage sintering model for the neck size ratio X/D as a function of sintering time t under isothermal conditions:

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