Effects of yttria content on the CMAS infiltration resistance of yttria stabilized thermal barrier coatings system
Effects of yttria content on the CMAS infiltration resistance of yttria stabilized thermal barrier coatings system
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DOI：
10.1016/j.jmst.2019.09.039
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发表时间：
2020-04
影响因子：
10.9
通讯作者：
J. J. G. Chavez-J.;R. Naraparaju;P. Mechnich;K. Kelm;U. Schulz;C. Ramana
中科院分区：
文献类型：
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作者：
J. J. G. Chavez-J.;R. Naraparaju;P. Mechnich;K. Kelm;U. Schulz;C. Ramana
研究了Y2 O3-ZrO 2基热障涂层中YO1.5掺杂对CMAS相互作用/渗透的影响。YO 1.5含量范围为43-67摩尔%的TBC（余量为ZrO 2）通过电子束物理气相沉积（EB-PVD）技术制备。结果表明，在氧化钇-氧化锆体系中，随着游离钇含量的增加，磷灰石的形成概率也随之增加。此外，抗渗透性和涂层消耗量似乎强烈依赖于涂层中YO1.5的含量。最薄的反应层和最低的渗透被发现为最高生产的67YO1.5涂层。补充XRD实验与火山灰/YO1.5粉末混合物具有更高的氧化钇含量比涂层（80 YO1.5和纯YO1.5）也显示出较高的磷灰石形成相对于增加氧化钇含量。发现促进基于磷灰石的反应产物的阈值组成在氧化锆中约为50YO1.5，这在涂层和XRD粉末实验中得到证实。一个YO1.5-ZrO 2-FeO-TiO 2轴承锆英石型相形成的反应产物，这意味着在熔体中的TiO 2作为一个触发器的锆英石形成的所有涂料组合物。该相对于CMAS/火山灰渗透抗性可能是有害的，因为它可以与磷灰石一起形成，磷灰石控制或限制可用于玻璃结晶的Y3+的量。富铁石榴石相含有所有可能的元素表现出较慢的成核相比，磷灰石和其生长增强与缓慢的冷却速率。讨论了在1250 °C下进行的测试的相稳定性和热处理对反应产物的影响。
The effects of YO1.5doping in yttria-zirconia based thermal barrier coatings (TBCs) against CMAS interaction/infiltration are discussed. The TBCs with an YO1.5content ranging from 43–67 mol.% (balance ZrO2) were produced by electron beam physical vapor deposition (EB-PVD) techniques. The results reveal a trend of higher apatite formation probability with the higher free YO1.5available in the yttria-zirconia system. Additionally, the infiltration resistance and amount of consumed coating appears to be strongly dependent on the YO1.5content in the coating. The thinnest reaction layer and lowest infiltration was found for the highest produced 67YO1.5coating. Complementary XRD experiments with volcanic ash/YO1.5powder mixtures with higher yttria contents than in the coatings (80YO1.5and pure YO1.5) also showed higher apatite formation with respect to increasing yttria content. The threshold composition to promote apatite-based reaction products was found to be around 50YO1.5in zirconia which was proved in the coatings and XRD powder experiments. An YO1.5-ZrO2-FeO-TiO2bearing zirconolite-type phase was formed as a reaction product for all the coating compositions which implicates that TiO2in the melt acts as a trigger for zirconolite formation. This phase could be detrimental for CMAS/volcanic ash infiltration resistance since it can be formed alongside with apatite which controls or limits the amount of Y3+available for glass crystallization. The Fe rich garnet phase containing all the possible elements exhibited a slower nucleation compared to apatite and its growth was enhanced with slow cooling rates. The implications of phase stability and heat treatment effects on the reaction products are discussed for tests performed at 1250 °C.