Pore size distributions calculated from 3-D images of DEM-simulated powder compacts

Numerical methods for determining pore size distributions from 3-D digitized microstructures of plastically compacted powders are presented. The microstructures are generated by simulations using the discrete element method (DEM). Two types of pore size distribution are considered: first, a "chamber" pore size distribution similar to the pore size distribution measured by quantitative metallography, second, a "throat" pore size distribution that takes into account percolation effects, and is similar to the pore size distribution measured by mercury intrusion porosimetry. The effect of sample size upon the numerically-determined mean pore size is examined. Some evidence that the "throat" pore size distributions accurately reproduce real mercury intrusion porosimetry results is given based upon porosimetry data from the literature. Finally, the evolution of the two types of pore size distribution with relative density is examined. Both homogeneous compacts of plastic spheres and mixtures of plastic and rigid-elastic spheres are studied. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.