(北京航空航天大学 材料科学与工程学院，北京 100191)
摘 要: 采用电子束物理气相沉积(EB-PVD)的方法在第二代镍基单晶高温合金N5上先后沉积Ru层和NiAlHf涂层。利用X射线衍射(XRD)、扫描电镜(SEM)、能谱仪(EDS)等研究Ru/NiAlHf涂层与合金基体在1 100 ℃的界面上的互扩散行为及高温循环氧化性能。结果表明：在扩散初期，涂层与合金基体界面上处形成了不连续的Ru2AlTa相，该相有效抑制了高温合金基体中难熔元素的外扩散，而当扩散时间延长至100 h时，该相消失，同时合金基体中形成了少量拓扑密堆相(P-TCP)，但未形成二次反应区(SRZ)。Ru/NiAlHf涂层在1 100 ℃循环氧化150h后氧化膜仍未出现显著剥落，表现出了良好的抗循环氧化性能。
关键字: 电子束物理气相沉积；单晶高温合金；二次反应区；互扩散；循环氧化
（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
