Packing and Sintering of Two-Dimensional Structures Made fro Bimodal Particle Size Distributions

Binary mixtures of spheres were used to prepare a variety of two-dimensional structures ranging from ordered to disordered. The extent of particle order was influenced by the size ratio and the concentration of the bimodal constituents. If either the sizes or the concentrations were very different, the structures became phase separated into ordered regions of small spheres and ordered regions of large spheres. Disordered structures were produced when particles were present in equal concentrations and when sizes differed by about 30%. The sintering behavior of these two-dimensional structures was also examined. The domain boundaries in the ordered samples were found to develop into cracks during sintering if the domain size was large. In contrast the disordered structures sintered homogeneously, without the formation of large processing defects.