High-temperature (1500 °C) interactions of promising environmental-barrier coating (EBC) ceramics in the rare-earth (RE) pyrosilicate system, Yb(2-x)YxSi2O7 (x = 0, 0.2, 1, or 2), with three different calcia–magnesia–aluminosiliate (CMAS) glass compositions, are explored. Only the Ca/Si ratio is varied in the CMAS: 0.76, 0.44, or 0.10. Interaction between the highest Ca/Si CMAS and the EBC ceramic with the lowest x (=0, Yb2Si2O7) promotes no reaction but the formation of “blister” cracks. In contrast, the highest x (=2, Y2Si2O7) promotes the formation of an apatite reaction product, but no “blister” cracks. Observationally, it is found that a decrease in the CMAS Ca/Si ratio (0.76–0.10) and a decrease in Y-content decreases the propensity for reaction crystallization (apatite formation) and “blister” cracks. These results are rationalized based on the relative affinities between Ca2+ in the CMAS and Y3+ or Yb3+ in the EBC ceramics, suggesting a way to tune the CMAS interactions in RE pyrosilicate solid solutions.

Yb （2- x） Y x Si 2 O 7（x = 0，0.2，1）在稀土（RE）焦硅酸盐体系中有希望的环境屏障涂层（EBC）陶瓷的高温（1500°C）相互作用或2），研究了三种不同的氧化钙-氧化镁-铝硅酸盐（CMAS）玻璃成分。在CMAS中，只有Ca / Si比有所变化：0.76、0.44或0.10。最高的Ca / Si CMAS与具有最低的x（= 0，Yb 2 Si 2 O 7）的EBC陶瓷之间的相互作用不会促进任何反应，但会形成“气泡”裂纹。相反，最高的x（= 2，Y 2 Si2 O 7）促进了磷灰石反应产物的形成，但没有“气泡”裂纹。观察到，发现CMAS Ca / Si比（0.76-0.10）的降低和Y含量的降低降低了反应结晶（磷灰石形成）和“水泡”裂纹的倾向。根据CMAS中的Ca 2+和EBC陶瓷中的Y 3+或Yb 3+之间的相对亲和力，可以合理地得出这些结果，从而提出了一种调节RE焦硅酸盐固溶体中CMAS相互作用的方法。