Calcium–magnesium–alumino-silicate (CMAS) particulates enter the aero-engine in a sandy environment, melt and infiltrate into 7 wt% yttria-stabilized zirconia (7YSZ) thermal barrier coatings (TBCs), reducing their lifetime. This leads to chemical degradation in 7YSZ accompanied by tetragonal to monoclinic phase transformation upon cooling. In this work, electron-beam physical vapor deposition coatings were infiltrated with a synthetic CMAS. Synchrotron X-ray diffraction measurements show that CMAS infiltration at 1250 °C has about 43% higher monoclinic phase volume fraction (PVF) at the coating surface compared to 1225 °C and remains consistently higher throughout the coating depth. Additionally, the increase in annealing time from 1 to 10 h results in a 31% higher monoclinic phase at the surface. Scanning electron microscopy revealed the presence of globular monoclinic phases corresponding spatially with the above findings. These results resolve the impact of time and temperature on CMAS infiltration kinetics which is important for mitigation.

中文翻译：

---

CMAS 渗透的 7YSZ 热障涂层的高能 X 射线相分析：时间和温度的影响

钙镁铝硅酸盐 (CMAS) 颗粒在沙质环境中进入航空发动机，熔化并渗入 7 wt% 氧化钇稳定氧化锆 (7YSZ) 热障涂层 (TBC)，从而缩短其使用寿命。这导致 7YSZ 中的化学降解伴随着冷却时的四方到单斜相转变。在这项工作中，电子束物理气相沉积涂层被合成 CMAS 渗透。同步加速器 X 射线衍射测量表明，与 1225°C 相比，1250°C 下的 CMAS 渗透在涂层表面具有约 43% 的单斜相体积分数 (PVF)，并且在整个涂层深度始终保持较高。此外，退火时间从 1 小时增加到 10 小时会导致表面单斜相增加 31%。扫描电子显微镜显示存在与上述发现在空间上对应的球状单斜晶相。这些结果解决了时间和温度对 CMAS 渗透动力学的影响，这对于缓解很重要。