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Effect of Nb Dopant on the Oxidation Behavior of Zr 2 [Al(Si)] 4 C 5 at 1000–1300°C
Author(s) -
Lu X. P.,
Zhou Y. C.
Publication year - 2011
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.1551-2916.2011.04564.x
Subject(s) - dopant , materials science , mullite , oxide , diffusion , solid solution , doping , hot pressing , chemical engineering , metallurgy , oxygen , chemistry , ceramic , organic chemistry , physics , optoelectronics , engineering , thermodynamics
Nb‐doped Zr 2 [Al(Si)] 4 C 5 solid solutions were prepared by in situ hot pressing method and their high‐temperature oxidation behavior at 1000°–1300°C were investigated. The oxidation resistance of [Zr 0.9 (Nb 0.1 )] 2 [Al(Si)] 4 C 5 solid solutions is improved remarkably compared with Zr 2 [Al(Si)] 4 C 5 without dopant. The improved oxidation resistance is due to the formation of a more protective oxide scale consisting of (Zr,Nb)O 2 , Nb 2 Zr 6 O 17 , Al 2 O 3 , and mullite, in which (Zr,Nb)O 2 solid solution is more effective than ZrO 2 in depressing the inward diffusion of oxygen. In addition, the decrease of cracks in the oxide scale above 1100°C in Nb‐doped sample is also beneficial to the improved oxidation resistance.