Abstract
The Wulff construction suggests that ceramic particles are polyhedral. Simulation experiments were carried out with plastic polyhedra (cuboctahedra, in particular). The packing structures of them were characterized in term of three different types of contacts-point, line, and face contacts. The measured percentage of them ranged from 17% to 23% for point contacts, 60% to 65% for line contacts and 15% to 20% for face contacts. A line contact model well described initial sintering of a commercially available alumina powder consisting of single crystalline particles. Microstructural development, current progresses of densification, grain growth and pore migration in the intermediate-stage are described with five simultaneous equations having four variables, which systematize reported theories on these phenomena.