As the inventor of the SLS process I must accept the blame for the
"sintering" misnomer. The word "sintering" is most commonly means
coalescence of ceramic or metal powders below melt temperature by atomic
diffusion. But there is a body of work in the literature describing the
coalescence of amorphous polymers or glasses by viscous flow driven by
surface tension. This is also called "sintering". An example:
Rosenzweig, N., Narkis, M., "Sintering Rheology of Amorphous Polymers",
Polym. Eng. Sci. 21 1167 (1981).
In SLS, the powder softens (amorphous materials) or melts (crystalline
materials) when heated by the laser. The powder then flows together due to
surface tension and gravity. The porosity of the SLS part is primarily a
function of the viscosity at the sintering temperature and the time at
temperature.
Hope that this helps.
Carl Deckard.
________________________________________________________
Dr. Carl Deckard
Assistant Professor of Mechanical Engineering
EIB205
Clemson University
P.O. Box 340921
Clemson South Carolina 29634-0921
(864) 656-5642
(864) 656-4435 fax
carl.deckard@ces.clemson.edu
________________________________________________________
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