Premium
Roles of Alumina in Zirconia for Functional Applications
Author(s) -
Guo Xin
Publication year - 2003
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/j.1151-2916.2003.tb03574.x
Subject(s) - grain boundary , electrical resistivity and conductivity , solubility , materials science , phase (matter) , solid solubility , boundary (topology) , cubic zirconia , mineralogy , condensed matter physics , metallurgy , chemistry , microstructure , solid solution , electrical engineering , ceramic , physics , mathematical analysis , engineering , mathematics , organic chemistry
The Al 2 O 3 addition to stabilized ZrO 2 has been studied for more than 20 years. In this article, literature and new results on the positive and negative effects of Al 2 O 3 additions on the electrical properties of ZrO 2 are summarized and analyzed. In particular, a comprehensive grain‐boundary conduction model is proposed. The Al 2 O 3 addition always increases the bulk resistivity, mainly because of the formations of defect associates and insulating Al 2 O 3 second‐phase particles. The Al 2 O 3 addition within the solubility limit increases the grain‐boundary resistivity, as a result of increased grain‐boundary space‐charge potential; the Al 2 O 3 addition above the solubility limit, however, scavenges the silicon‐rich second phase from the grain boundaries, thereby decreasing the grain‐boundary resistivity.