摘要
对电子束物理气相沉积(EB PVD)制备的由NiCoCrAlY粘结层和YSZ(YttriaStabilizedZirconia)陶瓷层组成的双层结构热障涂层,采用标准高温蠕变试验方法,研究了在高温、恒定外载荷作用下热障涂层中各层的形貌变化及裂纹的萌生、扩展,并探讨了涂层的失效过程和机理。垂直于试样轴向的断面观察表明,涂层在外力作用下氧化200h后层间裂纹非常明显,但几乎不发生在热氧化层(TGO)内,而是发生在陶瓷层与TGO层、TGO与粘结层之间,尤其发生在TGO与陶瓷柱状晶之间的等轴晶处。这种层间裂纹是在拉伸应力作用下,合金基体和粘结层发生径向收缩,而陶瓷层和TGO层的应变容限无法满足径向收缩而产生的。
High temperature creep testing is carried out to investigate the high temperature fatigue behavior of ceramic thermal barrier coatings（TBCs） prepared by electron beam- physical vapor deposition（EB-PVD）. It has been observed that the cracks are mainly formed in the interface between TGO（Thermally Grown Oxidation） layer and the ceramic top coating, instead of in the TGO layer just often observed during thermal cyclic testing without loading. Such cracks can be considered to be caused by the creep of metallic substrate along loading direction and the shrink in diameter of sample.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2005年第1期121-124,共4页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(50171003)
航空科学基金(03H51025)资助项目
