The degradation of thermal barrier coatings (TBCs) by molten silicates (CMAS) represents a fundamental barrier to progress in gas turbine technology, requiring a mechanistic understanding of the problem to guide the development of improved coatings. This article investigates the dissolution of yttria-stabilized zirconia (7YSZ and 20YSZ) into two model silicate melts at 1300–1400 °C. The approach involves the 1D dissolution of YSZ into a semi-infinite melt, characterizing the dissolution rates of YSZ and the diffusion rates of Zr⁴⁺ and Y³⁺ therein. The assessed kinetics of YSZ dissolution and diffusion were then applied to modeling the same phenomena on TBC-relevant length scales. These findings provide fundamental insight into (i) the dissolution mechanism of YSZ, (ii) the subsequent reprecipitation upon saturation, (iii) the quantitative effects of temperature and melt composition on the dissolution and diffusion kinetics, and (iv) how the measured kinetics manifests on the scale of flow channels present in TBCs.

熔融硅酸盐（CMAS）对热障涂层（TBC）的降解代表了燃气轮机技术发展的基本障碍，需要对问题进行机械理解以指导改进涂层的开发。本文研究了氧化钇稳定的氧化锆（7YSZ和20YSZ）在1300–1400°C下在两种模型硅酸盐熔体中的溶解。该方法涉及将YSZ一维溶解到半无限熔体中，表征YSZ的溶解速率以及Zr ⁴⁺和Y ^3+在其中的扩散速率。然后将评估的YSZ溶解和扩散动力学用于在TBC相关长度尺度上对相同现象进行建模。这些发现提供了基本的洞察（我）YSZ的溶解机理，（ii）饱和后的再沉淀，（iii）温度和熔体组成对溶解和扩散动力学的定量影响，以及（iv）所测得的动力学如何在当前流动通道的规模上表现出来在TBC中。