Liquid‐phase sintering of ZrO <sub>2</sub> ‐based nanocrystalline glass–ceramics achieved by multielement co‐doping
Le Fu, Bohan Wang, Ying Deng, Guofu Xu, Jiwu Huang, Håkan Engqvist, Wei Xia
Abstract
Abstract Liquid‐phase sintering (LPS) is an effective pathway to assist the densification of ceramics. However, it has seldom been used to densify glass–ceramics. In the present study, a multielement co‐doping strategy has been utilized to achieve LPS of a ZrO 2 –SiO 2 nanocrystalline glass–ceramic. Compared with undoped samples densified by solid‐state sintering, doping of equimolar Al, Y, and Ca promoted the densification of the glass–ceramic at lower temperatures with a faster densification rate. Ternary doping enhanced coarsening of ZrO 2 nanocrystallites during sintering and annealing. The distribution of dopants was carefully observed with X‐ray energy‐dispersive spectrometry technique in scanning electron transmission microscopy mode. Results showed that the three dopants showed different distribution behaviors. After sintering, Y dopants were predominately distributed in ZrO 2 nanocrystallites, whereas parts of Al and Ca dopants were distributed in ZrO 2 nanocrystallites and part of them co‐segregated at the ZrO 2 /SiO 2 heterointerfaces. Meanwhile, the segregation of Ca dopant at some intergranular films among ZrO 2 nanocrystallites was observed. Redistribution of dopants did not occur during annealing.