ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Models are developed to describe sintering of metal crystallites during heat treatment. The growth rate of such crystallites is assumed to depend upon particle migration over the surface of the support as well as on the rate the colliding particles merge (sinter) into a single unit. The theory predicts that the rate of decay of exposed metal surface area S is given as in Equation (1a). The exponent n is related to the assumed size dependence of the diffusion coefficients or of the rate constant of the merging process. It varies from 4 to 8 for diffusion controlled decay and it is less than 3 for sintering controlled decay, that is, when the rate controlling step is the merging of two colliding particles. Diffusion control is associated with strong interactions between the metal and the support, but in sintering control there is a weaker metal-support interaction.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690190222
