多元稀土掺杂YSZ热障涂层的热物理和热循环性能研究  

Thermophysical and Thermal Cycling Properties of Multi-element Rare Earth Doped YSZ Thermal Barrier Coatings

作　　者：黄光宏 甄真 王鑫 牟仁德 何利民 许振华 HUANG Guang-hong;ZHEN Zhen;WANG Xin;MU Ren-de;HE Li-min;XU Zhen-hua(Aviation Key Laboratory of Science and Technoogy 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2期1-9,共9页Vacuum

基　　金：国家科技重大专项(J2019-Ⅶ-0010-0150)。

摘　　要：4.5wt.%Gd_(2)O_(3)-5.5wt.%Yb_(2)O_(3)-10.5wt.%Y_(2)O_(3)-79.5wt.%ZrO_(2)(GdYbYSZ)稀土复合氧化物陶瓷是一类适用于更高温度下潜在应用的新型热障涂层(TBCs)材料。采用高温固相合成法制备了GdYbYSZ陶瓷粉体和陶瓷块材,在1 100℃和1 300℃煅烧不同时间后GdYbYSZ陶瓷粉末无相变,具有非常优异的高温相稳定性。在1 200℃时,GdYbYSZ陶瓷块材的平均热扩散系数和平均热导率分别比同等温度下YSZ陶瓷块材降低了2.1%和5.1%。采用电子束物理气相沉积(EB-PVD)工艺在单晶合金(Ni,Pt)Al粘结层表面制备了GdYbYSZ新型热障涂层。沉积态GdYbYSZ陶瓷涂层的主相结构为立方相,有少量游离态Y_(2)O_(3)和ZrO_(2)共存,其Y和Zr元素的相对含量均比靶材中的高,而Gd和Yb元素含量相当。经1 100℃长期冷热交替循环后,GdYbYSZ陶瓷层表面出现大量规则分布的“泥巴状”微观裂纹,陶瓷层内滋长的横向裂纹已经扩展到陶瓷层与TGO层的界面处,并引起该界面退化分离。陶瓷涂层的剥落位置主要出现在TGO层上下两个临域的界面处。TGO层严重的褶皱、波动起伏、扭曲交联、凸面尖端应力积聚和快速松弛是引起GdYbYSZ/(Ni,Pt)Al热障涂层体系层间界面分离和剥落失效的关键性因素。The rare earth oxide ceramic designed as 4.5wt.%Gd_(2)O_(3)-5.5wt.%Yb_(2)O_(3)-10.5wt.%Y_(2)O_(3)-79.5wt.%ZrO_(2)(GdYbYSZ)is a candidate material for thermal barrier coatings(TBCs),which will be suitable for application at higher temperatures.GdYbYSZ ceramic powders and bulks are fabricated by solid-state synthesis at temperatures above 1300℃,and the powders have no phase transformation and exhibit excellent thermal stability despite long-term calcination at 1100℃和1300℃.The averaged thermal diffusivity and thermal conductivity of GdYbYSZ ceramics are approximately 2.1%and 5.1%lower than those of the conventional YSZ bulk respectively.The GdYbYSZ ceramic coatings are directly manufactured on the surface of(Ni,Pt)Al bond coat by means of electron beam physical vapor deposition(EB-PVD),whose phase structure consists primarily of cubic phase with co-existing of excess Y_(2)O_(3) and ZrO_(2).Meanwhile,elemental compositions of Y and Zr within as-deposited ceramic topcoats are higher than those in the ingot,and the constituents of Gd and Yb elements in these two types of specimens tend to be similar.A large number of regularly distributed“mud-like”microcracks appear on the surface of GdYbYSZ ceramic coating after the long-term alternating thermal cycling at 1100℃.The transverse microcracks originating in the ceramic topcoat have elongated to the interface of ceramic coating and TGO layer that further cause the degeneration and separation of the interface.The spalling location of the GdYbYSZ ceramic coating mainly occurs at the upper and lower adjacent interfaces of the TGO layer.The serious rumpling,undulation,cross-linking,stress accumulation and rapid relaxation at the convex tip exist in the TGO layer are the critical factors to accelerating interfacial delamination and spallation failure of GdYbYSZ/(Ni,Pt)Al TBCs.

关 键 词：电子束物理气相沉积 热障涂层 热物理 热循环 剥落失效 

分 类 号：TB321[一般工业技术—材料科学与工程] TB43