Thermal Stability of Lanthanum Zirconate Plasma‐Sprayed Coating
Thermal Stability of Lanthanum Zirconate Plasma‐Sprayed Coating
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DOI：
10.1111/j.1151-2916.2001.tb00962.x
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发表时间：
2004-12
影响因子：
3.9
通讯作者：
Xueqiang Cao;R. Vaßen;W. Jungen;S. Schwartz;F. Tietz;D. Stöver
中科院分区：
文献类型：
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作者：
Xueqiang Cao;R. Vaßen;W. Jungen;S. Schwartz;F. Tietz;D. Stöver
锆酸镧（la2zr2o7， LZ）是一种新型热障涂层材料。通过长期退火和热循环研究了LZ涂层的热稳定性。在1400℃长期退火或热循环后，LZ粉末和等离子喷涂涂层均保持了焦绿石结构，并且通过x射线衍射观察到涂层中有较好的晶体生长方向。粉末中相当数量的la2o3在等离子火焰中蒸发，形成非化学计量涂层。此外，与标准的TBC材料ytria -稳定化氧化锆（YSZ）相比，LZ涂层具有较低的热膨胀系数，从而导致TBC体系中的应力水平较高。
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.