Sintering or Particle Coalescence

The sintering process is of particular importance in powder technology, although here the particles arc usually somewhat larger ( 30 jxm) than the conventional colloid range. 

A clearer fundamental understanding of sintering obviously depends upon a more complete knowledge of the surface tension of solids. 

If the solid particles are slightly soluble in the dispersion medium (or, if the medium is a gas, the solid is slightly volatile), then an alternative mechanism is available by which the system can reduce its surface area without the particles having to collide. Because of the phenomenon of surface tension the solubility of very small particles (or their vapour pressures) is greater than 

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