Yb_(2)O_(3)改性Gd_(2)Zr_(2)O_(7)热障涂层的显微组织和热循环性能研究  

Microstructure and Thermal Cycling Properties of Yb_(2)O_(3)Modified Gd_(2)Zr_(2)O_(7)Thermal Barrier Coatings

作　　者：李婷玥 王鑫 甄真 李娜 许振华 LI Ting-yue;WANG Xin;ZHEN Zhen;LI Na;XU Zhen-hua(Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Material,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院,航空材料先进腐蚀与防护航空科技重点实验室,北京100095

出　　处：《真空》2024年第5期21-29,共9页Vacuum

基　　金：国家科技重大专项(J2019-Ⅶ-0010-0150)

摘　　要：(Yb_(0.1)Gd_(0.9))2Zr_(2)O_(7)(YbGdZrO)稀土复合氧化物是适用于更高温度的新型热障涂层(TBCs)候选材料之一。采用电子束物理气相沉积(EB-PVD)工艺在单晶合金(Ni,Pt)Al粘结层表面分别制备了单陶瓷层YbGdZrO和双陶瓷层YbGdZrO/YSZ两种热障涂层,并对涂层的相结构、化学组成、显微形貌和热循环行为进行了表征分析。结果表明:沉积态YbGdZrO陶瓷涂层的主相结构为单一的缺陷型萤石相,并有少量Yb_(2)O_(3)共存;与单陶瓷层涂层相比,双陶瓷层涂层的柱状晶簇较为纤细,且可观察到明显的柱状晶间隙;双陶瓷层涂层1100℃热循环寿命约为单陶瓷层涂层的1.5倍;经长期冷热交替循环后,单陶瓷层涂层内横向裂纹滋长,并扩展到YbGdZrO/TGO层界面上方几微米处,导致界面退化分离,且陶瓷层中的Yb元素内扩散进入TGO层;双陶瓷层涂层内出现纵向裂纹,而YbGdZrO/YSZ和YSZ/TGO层间界面基本完好;热循环失效后,单陶瓷层和双陶瓷层试样TGO层内均出现横向和纵向裂纹,甚至进一步诱发了层内断裂分离现象。The rare earth composite oxide of(Yb_(0.1)Gd_(0.9))2Zr_(2)O_(7)(YbGdZrO)is a candidate material for novel thermal barrier coatings(TBCs),which can be potentially applied in higher temperatures.Both of single-ceramic-layer YbGdZrO and doubleceramic-layer YbGdZrO/YSZ TBCs were directly fabricated on top of(Ni,Pt)Al bond coat surface via electron beam physical vapor deposition(EB-PVD).The phase structure,chemical constituent,morphology and thermal cycling behavior of those TBCs were systematically investigated.The results show that the primary phase structure of the as-deposited YbGdZrO ceramic coating is single defective fluorite phase with co-existing of a small amount of Yb_(2)O_(3).Compared with the single-ceramic-layer coating,each beam of columnar crystal clusters in the sample with double-ceramic-layer TBC is relatively slender,and obvious columnar gain gaps can be observed.The 1100℃thermal cycling lifetime of double-ceramic-layer TBC is about 1.5 folds as that of singleceramic-layer YbGdZrO coating.After long-term alternating thermal cycling,the transverse microcracks grow in the single-ceramiclayer YbGdZrO coating and extend to several microns above the interface of YbGdZrO/TGO layer,causing interfacial degradation and separation.Moreover,the Yb element contained in single-ceramic-layer has inwardly diffused into the TGO layer.Longitudinal cracks appear within the double-ceramic-layer coating,while both of YbGdZrO/YSZ and YSZ/TGO interfaces remain basically intact.After thermal cycling failure,transverse and vertical microcracks are formed in the TGO layer of the single-ceramic-layer and double-ceramic-layer specimens,and even further induce the phenomenon of intra-layer fracture separation.

关 键 词：电子束物理气相沉积 热障涂层 改性锆酸钆 热循环 界面分离 

分 类 号：T32[一般工业技术]