Slow sintering in garnet‐containing Y and Gd zirconate–aluminate mixtures for thermal barrier coatings
Slow sintering in garnet‐containing Y and Gd zirconate–aluminate mixtures for thermal barrier coatings
复制标题
用于热障涂层的石榴石 - 含有 Y 和 Gd 锆酸盐 - 铝酸盐混合物的缓慢烧结
DOI：
10.1111/jace.19121
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发表时间：
2023
影响因子：
3.9
通讯作者：
Poerschke, David L.
中科院分区：
文献类型：
--
作者：
Yu, Yueh‐Cheng;Godbole, Eeshani P.;Berrios, Josselyne;Hewage, Nethmi;Poerschke, David L.
稀土锆酸盐和含有Y或Y + Gd的铝酸盐混合物形成两相石榴石-萤石混合物，在1400℃时烧结速度比纯萤石慢得多。在亚稳石榴石分解后，一种等价的无Y、含Gd的组合物形成钙钛矿铝酸盐而不是石榴石，显示出更快的致密化速度。在1500℃时，无Y样品的初始烧结速率也最快，而含Y + Gd样品的烧结速率差异更大。具有等摩尔Y + Gd的锆酸盐-铝酸盐在1500°C时致密化最慢，在250 h后保持~ 25%的孔隙率。研究结果强调了设计适应性热障涂层的可能性，该涂层可以在1400°C或更高的温度下保持显著的孔隙率。
Mixtures of rare‐earth zirconates and aluminates containing Y or Y + Gd that form a two‐phase garnet–fluorite mixture exhibit much slower sintering than pure fluorite at 1400°C. An equivalent Y‐free, Gd‐containing composition that forms a perovskite aluminate instead of garnet showed faster densification after the metastable garnet decomposes. At 1500°C, the Y‐free sample also showed the fastest initial sintering rate, whereas there was more divergence in the sintering rate for the samples containing Y + Gd. The zirconate–aluminate with equimolar Y + Gd shows the slowest densification at 1500°C and retains ∼25% porosity after 250 h. The results highlight possibilities for designing compliant thermal barrier coatings that can retain significant porosity at 1400°C or higher.