(北京航空航天大學(xué) 材料科學(xué)與工程學(xué)院，北京 100191)
摘 要: 采用電子束物理氣相沉積(EB-PVD)的方法在第二代鎳基單晶高溫合金N5上先后沉積Ru層和NiAlHf涂層。利用X射線衍射(XRD)、掃描電鏡(SEM)、能譜儀(EDS)等研究Ru/NiAlHf涂層與合金基體在1 100 ℃的界面上的互擴散行為及高溫循環(huán)氧化性能。結(jié)果表明：在擴散初期，涂層與合金基體界面上處形成了不連續(xù)的Ru2AlTa相，該相有效抑制了高溫合金基體中難熔元素的外擴散，而當(dāng)擴散時間延長至100 h時，該相消失，同時合金基體中形成了少量拓撲密堆相(P-TCP)，但未形成二次反應(yīng)區(qū)(SRZ)。Ru/NiAlHf涂層在1 100 ℃循環(huán)氧化150h后氧化膜仍未出現(xiàn)顯著剝落，表現(xiàn)出了良好的抗循環(huán)氧化性能。
關(guān)鍵字: 電子束物理氣相沉積；單晶高溫合金；二次反應(yīng)區(qū)；互擴散；循環(huán)氧化
（School of Materials Science and Engineering, Beihang University, Beijing 100191, China）
Abstract:A novel Ru/NiAlHf coating was deposited onto an Ni-based single crystal superalloy N5 by electron beam-physical vapor deposition(EB-PVD) of Ru and NiAlHf layer. The cyclic oxidation and interdiffusion of the Ru/NiAlHf coating at 1 100 ℃ was investigated by X-ray diffraction(XRD)and scanning electron micrograph (SEM) equipped with energy dispersive spectroscopy (EDS). The results show that the discontinuous Ru2AlTa phase forms at the interface of coating and substrate at initial diffusion stage, which effectively inhibits outward diffusion of refractory elements in the superalloy. The phase disappears after 100 h annealing. The Ru/NiAlHf coatings effectively suppress the formation of secondary reaction zone (SRZ). No apparent scale spallation is observed on the Ru/NiAlHf coating even after 150 h cyclic oxidation, indicating that the coatings exhibit a good cyclic oxidation-resistance.
Key words: electron beam-physical vapor deposition; single crystal superalloy; secondary reaction zone; interdiffusion; cyclic oxidation
