基体界面区的微观结构
(北京航空材料研究院 铸造高温合金研究室，北京 100095)
摘 要: 采用真空电弧镀的方法在定向凝固Ni3Al基合金IC6A上沉积NiCoCrAlYHf涂层，利用扫描电镜、透射电镜、电子探针能谱和X射线衍射技术研究了真空扩散处理态及在高温热曝下涂层/合金基体界面区的微观组织。研究结果表明：界面区由沉积层、扩散层和影响层组成，在1000℃曝晒100h后涂层和基体的界面未产生裂纹，扩散层和影响层的厚 度有所增加，沉积层中的β-NiAl相和α-Cr相数量减少，影响层中的块状相的尺寸和数量有所增加，并析出了一种杆状或针状的δ-NiMo相。界面区微观结构的变化与元素在涂层和基体间的相互扩散行为密切相关。
关键字: Ni3Al基合金；涂覆涂层；微观结构
between NiCoCrAlYHf overlay coating
and substrate of alloy IC6A
（Cast Superalloys Laboratory, Beijing Institute of
Aeronautical Materials, Beijing 100095, China）
Abstract:The directionally solidified Ni3Al base alloy IC6A was coated with NiCoCrAlYHf overlay coating by vacuum arc deposition method. The microstructure of interfacial area between NiCoCrAlYHf overlay coating and substrate of alloy IC6A was investigated with scanning electron microscopy(SEM), transmission electron microscopy(TEM), energy dispersive spectrum(EDS) technique of electron probe micro-analyzer(EPMA) and X-ray diffraction technique for specimens as annealed in vacuum and after high temperature exposure. The results show that the interfacial area is consisted of deposition layer, diffusion layer and influence layer. No cracks are found in the interface between the coating and the substrate for the specimen after exposure at 1000℃ for 100h. During high temperature exposure, the width of the diffusion layer and influence layer increase slightly, the volume percentage of β-NiAl phases and α-Cr phases in deposition layer decrease, the dimension and volume fraction of the bulk shape phases formed in the influence layer increase, and the rod like or needle like δ-NiMo phases precipitate in the influence layer. The microstructure change in the interfacial area is related to the inter-diffusion of elements between the coating and the substrate.
Key words: Ni3Al base alloy；overlay coating；microstructure
