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Electric current effect during the early stages of field‐assisted sintering
Author(s) -
Biesuz Mattia,
Rizzi Davide,
Sglavo Vincenzo M.
Publication year - 2019
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15976
Subject(s) - sintering , shrinkage , electric field , materials science , isothermal process , electric current , diffusion , current (fluid) , field (mathematics) , electrical current , composite material , metallurgy , thermodynamics , electrical engineering , physics , mathematics , quantum mechanics , pure mathematics , engineering
The linear shrinkage during isothermal treatment in the early stages of conventional and field‐assisted sintering of 8YSZ was analyzed. The results reveal that the application of a moderate electric current causes a remarkable acceleration of the self‐diffusion kinetics, resulting in an enhanced densification. In addition, when an electric current is applied, two different field‐assisted sintering regimes can be identified. The first one, observed at low currents (ie 5 mA/mm 2 ), is associated to sintering shrinkage which follows the conventional trend ( ε αt 1 / 3) although the densification is accelerated. The second regime takes place when larger current are applied (J > 10 mA/mm 2 ) and is described by a different sintering law, ε αt 1 / 7, this pointing out that the electric current causes the activation of alternative densification mechanisms when it exceeds a certain threshold value.