DOI number:10.1016/j.oceram.2025.100889
Journal:Open Ceramics
Abstract:In this study, we investigated the effects of amorphous SiO2 on the sintering mechanism and grain coarsening behavior of ZrO2 nanograins in ZrO2–SiO2 nanocrystalline ceramics (NCCs) during pressureless sintering (PLS). Two NCCs with different ZrO2/SiO2 molar ratios (65%:35% and 50%:50%) were fabricated and subsequently sintered via PLS. Their densification behavior and phase composition were analyzed. The SiO2 content had a significant effect on the activation of viscous flow sintering. The NCC containing 50 mol% SiO2 achieved high densification after sintering at 1210 °C, whereas a higher temperature of 1250 °C was required to enable significant densification in the NCC with 35 mol% SiO2. The crystallization of ZrO2 restricted the viscous flow of SiO2, thereby impeding the densification process. Hot isostatic pressing did not eliminate the residual pores remaining after PLS. The SiO2 matrix was capable of inhibiting the coarsening of ZrO2 nanograins by acting as a diffusion barrier. These findings reveal the dual effects of amorphous SiO2 during PLS and provide guidance for the fabrication of dense NCCs with minimal grain coarsening.
Co-author:Mingxi Deng, Zihua Lei
First Author:Le Fu*
Correspondence Author:Jiang Li*, Wei Xia*
Page Number:100889
Translation or Not:no
Links to published journals:https://www.sciencedirect.com/science/article/pii/S2666539525001567?via%3Dihub