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Electro‐Sintering of Yttria‐Stabilized Cubic Zirconia
Author(s) -
Kim SeungWan,
Kang SukJoong L.,
Chen IWei
Publication year - 2013
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.12291
Subject(s) - sintering , materials science , solid oxide fuel cell , yttria stabilized zirconia , microstructure , grain boundary , oxide , ceramic , grain growth , cubic zirconia , composite material , metallurgy , chemical engineering , anode , chemistry , electrode , engineering
Electro‐sintering, i.e., electrically enhanced densification without the assistance of Joule heating, has been observed in 70% dense 8 mol% Y 2 O 3 ‐stabilized ZrO 2 ceramics at temperatures well below those for conventional sintering. Remarkably, full density can be obtained without grain growth under a wide range of conditions, including those standard for solid oxide fuel cell ( SOFS ) and solid oxide electrolysis cell ( SOEC ), such as 840°C with 0.15 A/cm 2 . Microstructure evidence and scaling analysis suggest that electro‐sintering is aided by electro‐migration of pores, made possible by surface flow of cations across the pore meeting lattice/grain‐boundary counter flow of O 2− . This allows pore removal from the anode/air interface and densification at unprecedentedly low temperatures. Shrinkage cracking caused by electro‐sintering of residual pores is envisioned as a potential damage mechanism in SOFC / SOEC 8 YSZ membranes.