ANALYSIS OF 2-DIMENSIONAL PACKINGS

Using the computer simulation method, two-dimensional packings were constructed from circular particles, which simulate the structure of a powder compact. There have been considered packings of particles having a continuous log-normal size distribution with different widths, binary mixtures of monodisperse particles of fractions with a continuous log-normal size distribution and with different combinations of the mean fraction size and their volume concentration. For all packings their geometrical characteristics, e.g. geometrical density, mean particle coordination number, mean pore coordination number, and mean size of pores have been determined. In order to estimate the quality of packings from the standpoint of sinterability, a generalized criterion has been proposed which takes into account the principal factors affecting the sintering process. It has been demonstrated that an increase of density is not always accompanied by an improvement of the geometrical characteristics of a packing which can favor the sinterability. In particular, for some particle size distributions, an increase of density has been found to be associated with an increase of the mean pore coordination number and the mean size of pores. Practical recommendations are given on selecting the granulometric composition of powders for optimization of the sintering characteristics of compacts.