多层结构热障涂层的抗热震性能

Thermal Shock Resistance of Multilayer Thermal Barrier Coatings(TBCs)

采用电子束物理气相沉积技术(EB-PVD)在镍基单晶合金N5基体上制备了双层热障涂层(粘结层+陶瓷层)和三层热障涂层(粘结层+混合层+陶瓷层),并对2组涂层体系的热循环性能进行1100℃保温5 min水冷的热震实验,采用扫描电镜、能谱仪以及X射线衍射对其微观组织结构进行了分析。研究发现,在粘结层和陶瓷层之间添加的混合层(NiCrAlY+YSZ)能够延缓TGO层的生长,并具有缓解内应力的作用,两者的共同作用使得三层结构的热障涂层表现出更为优异的热匹配性。

Two layer and three layer TBCs were deposited by electron beam physical vapor deposition （EB-PVD） on the Ni-based superalloy （N5）. Thermal shock test of the coatings was carried out by heating the coating from room temperature to 1100 ℃ for 5 min, followed by water quenching. The microstructural characterization was analyzed by SEM, EDS and XRD. Results show that the mixture layer, composited by NiCrAlY and YSZ, can retard the growth of TGO layer and reduce the inter-stress between bond coating and top coating; thus the thermal matching performance of the three layers TBCs is better than that of the two laver TBCs.