Publications Details
Sintering damage during multi-material sintering
To generate data for comparison with the predictions of continuum sintering models for multi-material systems, several types of concentric cylinder samples were sintered to produce damage during sintering. The samples consisted of an outer ring of pressed ceramic powder (alumina or zinc oxide), the center of which was either fully or partially filled with a cylinder that consisted of either the same powder pressed to a higher green density (fully filled) or of previously densified 99% alumina (fully or partially filled). In addition, slots of various lengths were cut in some of the rings, from the outer surface parallel to the cylinder axis, which were then fully filled with dense alumina center cylinders and sintered. The types of sintering damage produced as the shrinkage of the rings was constrained by the center cylinders which shrank less or not at all, included shape deformation, cracking and possible density gradient formation. Comparisons of shrinkage measurements on rings fully filled with dense alumina center cylinders indicated that while the presence of the center cylinder increased the thickness and width shrinkage for both materials, the overall densification of the rings was impeded due to the decrease in circumferential shrinkage. This effect was more severe for the zinc oxide rings. The shape of the cross sections of the rings that were sintered either fully or partially filled with dense alumina center cylinders also showed differences depending on their composition.