Study on gradient structure and interface mechanical properties of n–8YSZ/AlCoCrFeNi high–entropy coatings
Study on gradient structure and interface mechanical properties of n–8YSZ/AlCoCrFeNi high–entropy coatings
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DOI：
10.1016/j.ceramint.2022.11.211
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发表时间：
2022-11
影响因子：
5.2
通讯作者：
Tao Ma;Taihong Huang;Chengzhi Hua;Chao Li;Xiaofeng Sun;Hongyan Sun;Peng Song
中科院分区：
文献类型：
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作者：
Tao Ma;Taihong Huang;Chengzhi Hua;Chao Li;Xiaofeng Sun;Hongyan Sun;Peng Song
采用大气等离子喷涂（APS）技术制备了纳米ZrO 2 -8%Y2O3（n-8 YSZ）/AlCoCrFeNi高熵粉末梯度涂层和双层涂层。梯度涂层的显微硬度变化与显微组织一致，梯度涂层的平均结合强度是双层涂层的2.50倍，表明梯度结构的涂层能够改善涂层的尖锐界面，并对提高涂层的结合强度起到显著的弥散增韧作用。450次热循环后，双层涂层出现横向扩展裂纹，并伴有涂层剥落。相比之下，垂直裂纹发生在梯度涂层内部，有效地增加了涂层的应变耐受性，提高了涂层的寿命。同时，在循环过程中，基体出现内氧化和裂纹，裂纹较为明显，双层涂层基体中出现架桥现象，梯度涂层保护下的基体产生不连续的微裂纹，表明梯度结构的涂层设计能有效释放内应力，提高涂层的抗热震性能。
In this study, gradient and double-layer coatings were prepared by atmospheric plasma spraying (APS) with nano ZrO2–8%Y2O3(n–8YSZ)/AlCoCrFeNi high–entropy powder. The microhardness of the gradient coating changed in a manner consistent with the microstructure, and the average bond strength of the gradient coating was 2.50 times higher than that of the double-layer coating, indicating that the gradient structure of the coating can improve the sharp interface of the coating, and play a significant role in dispersion toughening to improve the bond strength of the coating. After 450 thermal cycles, the double-layer coating exhibited transverse propagation cracks accompanying coating spalling. In contrast, vertical cracks occurred inside the gradient coating, effectively increasing the coating strain tolerance and improving the coating life. Simultaneously, internal oxidation and cracks appeared in the substrate during cycles, the cracks were more obvious, and bridging occurred in the substrate of the double-layer coating, the substrate under the protection of the gradient coating produced microcracks that were discontinuous, indicating that the design of the gradient structure of the coating can effectively release the internal stress and improve the thermal shock resistance of the coating.