基體界面區(qū)的微觀結(jié)構(gòu)
(北京航空材料研究院 鑄造高溫合金研究室，北京 100095)
摘 要: 采用真空電弧鍍的方法在定向凝固Ni3Al基合金IC6A上沉積NiCoCrAlYHf涂層，利用掃描電鏡、透射電鏡、電子探針能譜和X射線衍射技術(shù)研究了真空擴散處理態(tài)及在高溫熱曝下涂層/合金基體界面區(qū)的微觀組織。研究結(jié)果表明：界面區(qū)由沉積層、擴散層和影響層組成，在1000℃曝曬100h后涂層和基體的界面未產(chǎn)生裂紋，擴散層和影響層的厚 度有所增加，沉積層中的β-NiAl相和α-Cr相數(shù)量減少，影響層中的塊狀相的尺寸和數(shù)量有所增加，并析出了一種桿狀或針狀的δ-NiMo相。界面區(qū)微觀結(jié)構(gòu)的變化與元素在涂層和基體間的相互擴散行為密切相關(guān)。
關(guān)鍵字: Ni3Al基合金；涂覆涂層；微觀結(jié)構(gòu)
between NiCoCrAlYHf overlay coating
and substrate of alloy IC6A
SONG Jin-xia, LI Jian-ping
（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
