Liquid‐phase sintering of ZrO2‐based nanocrystalline glass–ceramics achieved by multielement co‐doping

Abstract

AbstractLiquid‐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 ZrO2–SiO2 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 ZrO2 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 ZrO2 nanocrystallites, whereas parts of Al and Ca dopants were distributed in ZrO2 nanocrystallites and part of them co‐segregated at the ZrO2/SiO2 heterointerfaces. Meanwhile, the segregation of Ca dopant at some intergranular films among ZrO2 nanocrystallites was observed. Redistribution of dopants did not occur during annealing.