Particle Packing, Compaction And Sintering In Powder Metallurgy
This thesis focuses on the improvement of density based on the controlhg of particle packing and the subsequent densification processes. Fist, the two-sphere mode1 for monosized powder to determine the lattice diffiision contribution in sintering is considered. Based on Eadie's model, two new solutions are developed and presented, an upper lirnit solution with dace curvature at a maximum al1 dong the neck and a more accurate solution in which the form of the surface curvature at the neck can be varied as appropriate. Producing birnodal powder distribution powder metallurgy (Pl4 parts is next considered. It is shown that this technique is capable of producing parts with exceilent final densities and mechanical properties. In order to explain the above expenrnental results, theoretical research about bimodal powder is focused on particle packing. The first theoretical tool is the coordination number of the particles a...