Yb₂Si₂O₇ coatings were deposited on Si/SiC substrates by atmospheric plasma spray (APS). The different power and plasma chemistries used in this work produced mainly amorphous crack-free coatings with compositions shifted to lower SiO₂ content with higher power and H₂ flow. Differences in microstructure and thermomechanical properties (crystallization behavior, thermal expansion coefficient and thermal conductivity) of as-deposited and thermally treated coatings were directly related to the evolution from amorphous to crystalline phases. A Yb₂SiO₅ metastable phase was identified after thermal treatments at temperatures ∼ 1000 °C that transformed to its stable isomorph at 1220 °C. This transformation, followed by the growth of the crystal cell volume, promoted the coating expansion and the “healing” of microcracks present in the amorphous as-sprayed coating.

通过大气等离子体喷涂（APS）在Si / SiC衬底上沉积Yb ₂ Si ₂ O ₇涂层。在这项工作中使用的不同功率和等离子体化学方法主要生产出无定形的无裂纹涂层，其组成随着高功率和H ₂流动而转移到较低的SiO ₂含量。沉积和热处理涂层的微观结构和热机械性能（结晶行为，热膨胀系数和热导率）的差异与非晶相向结晶相的演变直接相关。Yb ₂ SiO ₅在约1000°C的温度下进行热处理后鉴定出亚稳相，并在1220°C时转变为稳定的同晶型。这种转变，随后是晶胞体积的增长，促进了涂层的扩展和无定形喷涂涂层中存在的微裂纹的“修复”。