Abstract

In this work, the effect of sol–gel deposited top-coat on thermal fatigue resistance of thermal barrier coatings (TBCs) subjected to thermal fatigue loading is evaluated experimentally. To obtain non-conventional sol–gel thermal barrier coatings (SGTBC), coated samples underwent thermal fatigue loading at 1100 °C for 10 min heating and cooling. The tested sol–gel thermal barrier coatings were then compared to conventional air plasma sprayed (APS) thermal barrier coatings as well. The life of samples was investigated as a function of number of sustaining thermal cycles to times. Furthermore, the performed experiment was analyzed using scanning electron microscope, energy dispersive spectroscopy and X-ray diffractometer. The obtained results indicated that the non-conventional sol–gel thermal barrier coatings exhibited 1.46 times better thermal fatigue life in IN800SGTBC against 1.31 times thermal fatigue life of IN718SGTBC but overall thermal fatigue life was found to be better in IN718 SGTBC, signified effects of metallic substrates in thermal fatigue life determination. However, the nanostructured SGTBC had higher thermal cyclic resistance than conventional APS TBC, resulted in improved lifetime indicating the increased adherence at the substrate interface. Results also showed that the dominant failure mechanism of TBCs was destabilization of top-coat (YSZ), resulting composition of (Al, Cr)₂O₃ and spinel as reaction products for depleting Y₂O₃ producing from yttria stabilized zirconia (YSZ). Furthermore, the results showed that the amount of the porosity percent in the sol–gel TBCs was 2.3% higher than the conventional TBCs.

Graphic Abstract

Figure: Material Processing, and thereafter testing analysis for present work.

中文翻译：

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热循环载荷作用下Sol-Gel合成IN800热障涂层的研究：金属基材的影响

摘要

在这项工作中，通过实验评估了溶胶-凝胶沉积面漆对承受热疲劳载荷的热障涂层（TBC）的抗热疲劳性的影响。为了获得非常规的溶胶-凝胶热障涂层（SGTBC），已涂层的样品在1100°C承受了10分钟的加热和冷却后的热疲劳载荷。然后将经过测试的溶胶-凝胶隔热涂层也与传统的空气等离子喷涂（APS）隔热涂层进行比较。研究样品的寿命与维持热循环次数的关系。此外，使用扫描电子显微镜，能量色散光谱和X射线衍射仪分析了进行的实验。获得的结果表明，非常规的溶胶-凝胶热障涂层表现出1。IN800SGTBC的热疲劳寿命比IN718SGTBC的1.31倍高46倍，但发现IN718 SGTBC的总体热疲劳寿命更好，这表明金属基材在热疲劳寿命测定中的作用。但是，纳米结构的SGTBC比常规的APS TBC具有更高的热循环阻力，从而提高了使用寿命，表明在基材界面处的粘附性增加。结果还表明，TBC的主要失效机理是面涂层（YSZ）失稳，从而导致（Al，Cr）的组成 纳米结构的SGTBC比常规的APS TBC具有更高的热循环阻力，从而延长了使用寿命，表明在基材界面处的粘附性增加。结果还表明，TBC的主要失效机理是面涂层（YSZ）失稳，从而导致（Al，Cr）的组成 纳米结构的SGTBC比常规的APS TBC具有更高的热循环阻力，从而延长了使用寿命，表明在基材界面处的粘附性增加。结果还表明，TBC的主要失效机理是面涂层（YSZ）失稳，从而导致（Al，Cr）的组成₂ O ₃和尖晶石是消耗由氧化钇稳定的氧化锆（YSZ）产生的Y ₂ O _3的反应产物。此外，结果表明，溶胶-凝胶TBC中的孔隙度百分比量比常规TBC高2.3％。

图形摘要

图：材料处理，然后进行当前工作的测试分析。