THE MORPHOLOGY OF HIGH-VOLUME FRACTION SOLID-LIQUID MIXTURES - AN APPLICATION OF MICROSTRUCTURAL TOMOGRAPHY

Three-dimensional (3-D) images of the skeletal morphology that forms a t a high volume fraction of solid during Ostwald Ripening are reconstr ucted from two-dimensional (2-D) sections. These images illustrate the topology of the skeleton, including the circuitous and multiple paths through which particles in the skeleton connect. Particles that conne ct by grain boundaries form chains that can cross-link and intersect. These chains can also give rise to multiple indirect contacts between two particles. Direct interparticle contacts can occur via grain bound aries or thin liquid films. All particles connect to the skeletal netw ork by such ''contacts''; there are no isolated particles or clusters within our 3-D reconstruction. Shape accommodation is prevalent. The p article morphology is a strong function of the spatial arrangement of neighboring particles. We find that isolated 2-D sections are thus lim ited in characterizing the microstructure. The relationship between th e 3-D microstructure of the skeleton and its structural stability is d iscussed. (C) 1997 Acta Metallurgica Inc.