Synthesis and densification of BaZrO3 ceramics by reactive cold sintering of Ba(OH)2⋅8H2O-Zr(OH)4 powders

Abstract

Reactive cold sintering (RCS) is a combination of a low-temperature reaction and the cold sintering process, and it is used for the direct synthesis and simultaneous consolidation of ceramic powders. Here, we investigated RCS of BaZrO3 through the reaction between Ba(OH)2⋅8H2O and Zr(OH)4, and obtained pure BaZrO3 compacts with a relative density of ∼92% under the conditions of Zr(OH)4 ball-milling for 30 min, Ba/Zr ratio of 1.15, and holding a temperature of 350 °C for 60 min. The effects of processing parameters on the phase structure, relative density, microstructure evolution, and dielectric property of the BaZrO3 bulk were studied in detail. The results suggest that the synthesis and densification of BaZrO3 bulk in the RCS process involved the steps of dissolution, reaction, agglomeration, collapse, and densification. The present study extends the applicability of RCS to the preparation of high-density perovskite ceramics with nanograins.