Analysis of agglomerated packings

Results of computer simulation of the packing of particles in compacts from agglomerated powders are presented. The effect of the characteristics of agglomerated powders, such as the number of particles in the agglomerates, the size distribution of agglomerates, and the volume share of the fine fraction (individual particles) on the factors that determine the sinterability of compacts, i.e., the density, the mean number of contacts per particle, and the mean size and the mean coordination number of the pores, is investigated. It is established that compared to compacts from individual particles the presence of agglomerates sharply worsens the packing characteristics. The worst effect is due to agglomerates containing less that 30 – 40 particles. The packing characteristics can be improved by using powders with a wide size distribution of agglomerates or by adding unagglomerated particles. It is interesting that computer models of powder compacts can be used for predicting the strength properties of the materials sintered from these powders. Data on the influence of the packing characteristics on the mean strength and the Weibull modulus are presented.Translated from Ogneupory, No. 4, pp. 14–17, April, 1995.