from the conferences organized by TANGER Ltd.
The impact of GeO2 on the sintering kinetics and mass transfer mechanisms in tetragonal zirconia nanopowders has been investigated. The shrinkage kinetics of 3Y-TZP was investigated by the dilatometry analyses. The constant rate of heating method was used to determine the dominant mass transfer mechanisms at the initial sintering stage. It was found that GeO2 in depends on the synthesis method and its amount caused the viscous flow mechanism participation at the initial sintering stage. The sintering mechanism in co-precipitated 3Y-TZP-GeO2 powders was changed from volume diffusion mechanism to the volume diffusion with viscous flow mechanism. In mixed 3Y-TZP-GeO2 powders, the sintering mechanism changed from grain boundary diffusion to the volume diffusion with viscous flow mechanism participation. In both types of nanopowders such sintering mechanism changing leads to the activation energy of sintering decreasing that reduces a sintering temperature and activates the densification process in 3Y-TZP.
Keywords: Zirconia, nanopowders, nanocomposites, sintering, additives.© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.