Cu-Nb合金薄膜的微观结构与辐照损伤  

Microstructure and Radiation Damage of Cu-Nb Alloy Thin Films

作　　者：于开元 李彦[1] 孙祎帆 张干 张展瑄 Yu Kaiyuan;Li Yan;Sun Yifan;Zhang Gan;Zhang Zhanxuan(College of New Energy and Materials,China University of Petroleum-Beijing,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)新能源与材料学院,北京102249

出　　处：《稀有金属》2021年第3期372-377,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51501225)资助。

摘　　要：采用真空磁控溅射共溅法制备了CuxNb100-x(x=15,25,35,50,65,75,85,%,原子分数)7种成分的合金薄膜,采用氦(He)离子注入手段对合金薄膜进行室温辐照改性,利用X射线衍射仪(XRD)、透射电子显微镜(TEM)和纳米压痕仪研究了辐照前后合金薄膜的微观形貌、相组成与力学特性。结果显示:当Cu含量≤25%或≥75%时,合金薄膜由单一晶体相构成,晶粒形貌为等轴晶,尺寸约为100 nm,前者晶界处有Cu富集,后者晶界处有Nb富集;经He离子辐照后,He泡均匀分布于晶粒内,未见明显偏聚;辐照后样品的纳米压痕硬度显著高于未辐照样品,呈现辐照硬化。当Cu含量为35%~65%时,合金薄膜由晶体与非晶双相构成,其中晶体相为颗粒状,尺寸为10~20 nm,均匀分布于非晶基体中;经He离子辐照后,He泡主要分布于晶体/非晶界面处,晶体或非晶相内部的He泡难以分辨;辐照后样品的纳米压痕硬度低于未辐照样品,呈现辐照软化。Understanding the microstructural response of metals and alloys to the radiation of particles,such as electrons,neutrons,protons and ions,is vital for the service extension of the existed nuclear materials and the development of new radiation-tolerant structural materials for the next generation nuclear energy. It has been shown for decades that the interfaces in metals and alloys are effective in capturing and sinking the radiation-induced point defects and defect clusters,leading to enhanced radiation tolerance. In this study,we have obtained abundant crystal/amorphous interfaces in Cu-Nb alloy thin films,which were later on subject to He ion irradiation. The microstructure and indentation hardness of the pristine and irradiated specimens have been studied and compared. Seven CuxNb100-x(x=15,25,35,50,65,75,85(%,atom fraction))thin film specimens were deposited on oxidized single crystal silicon(100)substrates using magnetron co-sputtering technique at room temperature. The as-deposited thin film specimens were irradiated by 100 keV He ions to the dose of 6×1020 m-2 at room temperature in a vacuum chamber. X-ray diffraction(XRD)results showed that the Cu-Nb thin films were composed of single crystalline phase when the Cu content was ≤25% or ≥75%,as indicated by the exclusive Cu or Nb peaks. Transmission electron microscopy(TEM)images revealed that the grains were equiaxed and the average grain size was about 100 nm. Nb-rich or Cu-rich regions were observed at the grain boundaries owing to the high intermixing enthalpy between Cu and Nb. When the Cu content ranged from 35% to 65%,the Cu-Nb thin films were composed of both crystalline and amorphous phases.The crystalline phase was in the form of particles,which embedded uniformly in the amorphous matrix. All of the dual phase specimens showed a wide peak between Cu(111)and Nb(110)in the XRD pattern. The wide peak moved towards Cu(111)with the increasing of Cu content and vice versa. After He irradiation,the He bubbles were observed to reside uniformly within

关 键 词：Cu-Nb合金 薄膜 辐照损伤 非晶 

分 类 号：TG146.11[一般工业技术—材料科学与工程]