Plastic flow of saturated, consolidated alumina powder compacts: Particle size and binary mixtures

The flow stresses and relaxed yield stresses of saturated, alumina powder c ompacts that have been consolidated via pressure filtration were measured i n unconstrained uniaxial compression. Two different sized powders, as well as binary mixtures of the two powders, were investigated. Bodies that were consolidated from slurries of larger par; tides had lower flow and relaxed yield stresses, relative to bodies that were made of small particles with t he same relative density and solution conditions. This result is primarily due to the lower number of particle-particle contacts per unit volume in th e body that was made of the large particles. The flow stress of the body ca n be controlled by adjusting the fraction of large particles to small parti cles.