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Sintering kinetics of ZrO 2 nanopowders modified by group IV elements
Author(s) -
Lakusta Marharyta,
Danilenko Igor,
Volkova Galina,
Loladze Larisa,
Burkhovetskiy Valeriy,
Doroshkevich Oleksandr,
Brykhanova Irina,
Popova Inna,
Konstantinova Tetyana
Publication year - 2019
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13215
Subject(s) - sintering , materials science , activation energy , cubic zirconia , grain boundary diffusion coefficient , diffusion , coprecipitation , kinetics , chemical engineering , mass transfer , shrinkage , metallurgy , composite material , grain boundary , ceramic , microstructure , thermodynamics , chemistry , physics , quantum mechanics , engineering
The sintering behavior of tetragonal zirconia nanopowders modified by the group IV elements at the initial sintering stage was investigated. It was found that different additives SiO 2 , SnO 2 , and GeO 2 have a significant influence on the densification kinetics of 3Y‐TZP nanopowders obtained by coprecipitation during sintering as it depends on the amount of additives (0‐5 wt%). The shrinkage of zirconia‐based specimens during the nonisothermal sintering was analyzed using the dilatometric data. The constant rate of heating technique was applied in order to determine the dominant mass transfer mechanism at the initial stage of sintering in modified zirconia nanopowders. It was found that there was a change in the mass transfer mechanism and diffusion activation energy in 3Y‐TZP as a result of the additives. The dominant sintering mechanism in 3Y‐TZP changed from the volume diffusion to the grain boundary diffusion due to the addition of SiO 2 and SnO 2 and the sintering activation energy increased in these cases. However, GeO 2 additive activated the viscous flow mechanism in sintering process of 3Y‐TZP nanopowders which led to acceleration of the densification due to the decrease in the diffusion activation energy.