Preparation of zircon bodies from amorphous precursor powder synthesized by sol-gel processing

Comments concerning both synthesis conditions and characteristics of the amorphous zircon precursor powder, which already have been published, lead us to propose a schematic representation of powder grains. The sintering of the precursor powder during the calcination treatment is similar to a “moderate” sintering, which can be justified by the different nature of primary particles composing the grains. The sintering of green bodies prepared from the precursor powder compacted then isostically pressed, is possible at temperatures as low as 1200 °C. The sintered bodies exhibit a high relative density, close to 95%, but their microstructure reveals the presence of cracks that the morphology of synthesized zircon could be sufficient to justify.