Influence of rare earth elements on the structure and properties of powders based on zirconium dioxide during consolidation

Abstract

Zirconium oxide powders with different contents of REE concentrate (La, Nd, Pr) in an amount from 25 to 35 mol. % were synthesized by the method of reverse chemical deposition. The effect of the annealing temperature in the range of 600–1200 ° C on the phase transformations of the synthesized powders has been investigated by Raman spectroscopy. It was found that the formation of REE zirconates with a pyrochlore structure occurs after annealing at a temperature of 1000 ° C. At higher annealing temperatures, the presence of tetragonal ZrO2 was noted in the samples with a lower concentrate content in the phase composition. A study of the influence of the sintering temperature of 1400-1600 °C on the densification processes, phase composition and microstructure of ceramic materials based on REE zirconates has been carried out. It has been shown that the densification processes proceed most slowly in a ceramic material with 35 mol.% of rare-earth oxides, and at all sintering temperatures it has a stable phase composition, consisting mainly of rare-earth zirconates with a pyrochlore structure.