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Thermal Stability of Lanthanum Zirconate Plasma‐Sprayed Coating
Author(s) -
Cao X. Q.,
Vassen R.,
Jungen W.,
Schwartz S.,
Tietz F.,
Stöver D.
Publication year - 2001
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.1151-2916.2001.tb00962.x
Subject(s) - thermal barrier coating , materials science , yttria stabilized zirconia , coating , cubic zirconia , thermal expansion , temperature cycling , pyrochlore , zirconate , composite material , thermal stability , lanthanum , annealing (glass) , thermal spraying , chemical engineering , ceramic , thermal , inorganic chemistry , chemistry , titanate , physics , organic chemistry , meteorology , engineering , phase (matter)
Lanthanum zirconate (La 2 Zr 2 O 7 , LZ) is a newly proposed material for thermal barrier coatings (TBCs). The thermal stability of LZ coating was studied in this work by long‐term annealing and thermal cycling. After long‐term annealing at 1400°C or thermal cycling, both LZ powder and plasma‐sprayed coating still kept the pyrochlore structure, and a preferred crystal growth direction in the coating was observed by X‐ray diffraction. A considerable amount of La 2 O 3 in the powder was evaporated in the plasma flame, resulting in a nonstoichiometric coating. Additionally, compared with the standard TBC material yttria‐stabilized zirconia (YSZ), LZ coating has a lower thermal expansion coefficient, which leads to higher stress levels in a TBC system.