The article addresses effects of silicate deposit composition on reactions with yttrium monosilicate (YMS), a candidate environmental barrier coating for aero‐engine components. Computed phase equilibria are used to predict the nature and relative proportions of reaction products and the extent of YMS consumption upon reaction with twelve deposits of varying composition at 1300°C. These predictions are compared with results of a corresponding experimental study on three exemplary deposits. Although the nature and sequence of reaction products formed (typically apatite and yttrium disilicate) depend on the Ca:Si ratio of the deposit, the degree of consumption of YMS at equilibrium is relatively insensitive to deposit composition and is predicted to proceed to a greater extent than that in yttrium disilicate. However, sluggish reaction kinetics associated with the formation of a thin apatite layer above the YMS prevents reactions from reaching their terminal equilibrium states within the experimental times investigated (250 hours). For deposit loadings of 18 mg/cm² (corresponding to a thickness of about 100 µm), the degree of consumption following 250 hours exposures is only about 10%‐40% of the predicted terminal values, depending on deposit composition.

中文翻译：

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熔融硅酸盐沉积物与单硅酸钇的反应

本文探讨了硅酸盐沉积物成分对与单硅酸钇（YMS）的反应的影响，后者是航空发动机部件的候选环境屏障涂料。计算出的相平衡用于预测反应产物的性质和相对比例，以及在1300°C下与十二种不同组成的沉积物反应时YMS消耗的程度。将这些预测与对三个示例性矿床的相应实验研究的结果进行了比较。尽管形成的反应产物的性质和顺序（通常是磷灰石和二硅酸钇）取决于沉积物的Ca：Si比，但平衡状态下YMS的消耗程度对沉积物的组成相对不敏感，并且预计会在更大程度上进行比二硅酸钇中的要高。然而，与YMS上方形成薄磷灰石层相关的缓慢的反应动力学，阻止了反应在研究的实验时间内（250小时）达到其最终平衡状态。对于18 mg / cm的沉积物载荷²（对应于约100 µm的厚度），暴露250小时后的消耗程度仅为预计最终值的10％-40％，具体取决于沉积物的成分。