Physical Processes Involved in Sintering

JSGT 1947 V31 T264-T266

The shrinkage occurring when pressed powders are fired is a manifestation of the tendency of the material to reduce its surface energy to a minimum. The surface forces act locally at the contacts between particles and tend to broaden these areas. The elastic forces resident in the particles resist such deformation, but become relatively (as well as absolutely) less powerful as the temperature is raised. Small particles are more adhesive than large ones on account of the greater ease with which this broadening takes place when the disparity between the particle size and the range of action of the surface forces is diminished.

D. H. Bangham