Calcium‐magnesium‐alumino‐silicates (CMAS) melt attack has been a critical issue for the thermal barrier coatings (TBCs) with ever‐increasing engine operating temperature. In this study, a novel CMAS‐resistant material apatite‐type Gd₁₀(SiO₄)₆O₃ is developed for TBCs application based on thermodynamic equilibrium design. The chemical reaction of Gd₁₀(SiO₄)₆O₃ bulk and CMAS melt is investigated at 1300°C. The CMAS corrosion resistance of Gd₁₀(SiO₄)₆O₃ bulk is evaluated and compared with the well‐studied CMAS‐resistant material Gd₂Zr₂O₇ (GZO). It is found that Gd₁₀(SiO₄)₆O₃ shows a significantly enhanced CMAS resistance, including lower intrinsic CMAS infiltration rate (~1.09 μm/h^1/2) and smaller infiltration upper limit (50‐62 μm) for a 20 mg/cm² CMAS deposition. More importantly, for Gd₁₀(SiO₄)₆O₃, the CMAS infiltration only alters the composition but does not change the crystal structure or destroy microstructural integrity. The reaction mechanism is elucidated as following two stages: (a) surface Gd₁₀(SiO₄)₆O₃ quickly transforms into Ca₂Gd₈(SiO₄)₆O₂ in suit by interdiffusion with CMAS melt and then is thermodynamically stable with CMAS melt, thereby effectively inhibiting the further CMAS infiltration and (b) with the ongoing interdiffusion of Gd/Ca, the CMAS‐infiltrated layer slowly thickens and follows a parabolic law. Meanwhile, the CMAS melt gradually precipitates Ca₂Gd₈(SiO₄)₆O₂ and CaAl₂Si₂O₈ (anorthite) until the melt is exhausted.

中文翻译：

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基于热力学平衡设计的新型耐CMAS材料：磷灰石型Gd10（SiO4）6O3

钙镁铝硅酸盐（CMAS）的熔体侵蚀一直是发动机工作温度不断升高的隔热涂层（TBC）的关键问题。在这项研究中，基于热力学平衡设计，针对TBC应用开发了一种新型的耐CMAS材料磷灰石型Gd ₁₀（SiO ₄）₆ O ₃。在1300℃下研究了Gd ₁₀（SiO ₄）₆ O ₃体与CMAS熔体的化学反应。对Gd ₁₀（SiO ₄）₆ O ₃块体的CMAS耐腐蚀性进行了评估，并与经过充分研究的耐CMAS材料Gd进行了比较。₂ Zr ₂ O ₇（GZO）。发现Gd ₁₀（SiO ₄）₆ O ₃表现出显着增强的CMAS抵抗力，包括20℃时较低的固有CMAS渗透率（〜1.09μm / h ^1/2）和较小的渗透上限（50-62μm）。 mg / cm ² CMAS沉积。更重要的是，对于Gd ₁₀（SiO ₄）₆ O ₃，CMAS渗透只会改变成分，而不会改变晶体结构或破坏微结构完整性。阐明了以下两个阶段的反应机理：（a）表面Gd ₁₀（SiO₄）₆ O ₃通过与CMAS熔体相互扩散而迅速转变为适合的Ca ₂ Gd ₈（SiO ₄）₆ O ₂，然后与CMAS熔体热力学稳定，从而有效地抑制了CMAS的进一步渗透，以及（b）正在进行的相互扩散在Gd / Ca的作用下，CMAS渗透层缓慢增厚并遵循抛物线定律。同时，CMAS熔体逐渐沉淀Ca ₂ Gd ₈（SiO ₄）₆ O ₂和CaAl ₂ Si ₂ O ₈（钙长石），直到熔体耗尽。