锆合金包壳Cr涂层界面元素扩散行为研究进展  

Research Progress Regarding Interfacial Element Diffusion Behavior of Chromium Coating on Zirconium Alloy Cladding

作　　者：吴金龙 栾佰峰[1] 周虹伶 杨晓玲 黄伟九 孙超[3] WU Jinlong;LUAN Baifeng;ZHOU Hongling;YANG Xiaoling;HUANG Weijiu;SUN Chao(College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China;Institute of New Materials Technology,Chongqing University of Arts and Sciences,Chongqing 402160,China;Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu 610213,China)

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆文理学院新材料技术研究院,重庆402160 [3]中国核动力研究设计院反应堆燃料及材料重点实验室,成都610213

出　　处：《表面技术》2024年第10期16-27,共12页Surface Technology

基　　金：国家自然科学基金项目(U20A20232,U1867202)。

摘　　要：随着核反应堆向高燃耗和更长服役寿命方向发展,对包壳材料的安全可靠性提出了更高的要求。锆合金表面Cr涂层由于其优异的抗高温氧化性能、耐腐蚀性能以及与基体良好的兼容性,被认为是最有前景的耐事故涂层包壳材料。综述了近年来涂层Cr与基体Zr界面元素扩散行为的研究成果,重点介绍了Cr涂层不同状态下的界面结构及演变规律,包括沉积、退火、辐照、氧化等状态。总结了Cr的扩散、分布和金属间化合物Zr-Cr-(Fe)层的生长动力学模型,归纳了界面扩散对涂层结构及性能的不利影响。扩散阻挡层是一种抑制涂层与基体互扩散的有效结构,介绍了阻挡层设计制备原则以及现有的和潜在的金属或陶瓷阻挡层材料,分析了2类典型阻挡层的优缺点。金属阻挡层能抑制Cr的扩散并延迟Cr-Zr共晶反应,但需要考虑中子经济性;虽然陶瓷阻挡层阻隔元素扩散的性能优异,但由于其与锆合金力学性能和热膨胀系数的差异明显,易产生微裂纹,需要考虑其抗裂性。最后提出了采用实验与分子动力学等相结合的多尺度研究方法开展界面研究,同时指出了目前研究工作中亟待解决的关键问题,这为后续的锆合金表面耐事故涂层研究与开发提供了重要参考。With the development of nuclear reactors toward high fuel consumption and longer service life,higher requirements are placed on the safety and reliability of cladding materials.In order to address the nuclear fuel design defects exposed during the Fukushima nuclear accident,the research on accident tolerant fuel(ATF)has been carried out.Among several ATF cladding concepts,surface coating is the most promising strategy for engineering applications in the short term.Due to its excellent high-temperature oxidation resistance,corrosion resistance,and good compatibility with the substrate,Cr coating is considered to be the most promising accident resistant coating cladding material.The research results on element diffusion behavior at the Cr coating/substrate Zr interface in recent years were reviewed,focusing on the interface structure and evolution rules of Cr coatings in different states,including deposition,annealing,irradiation,oxidation and other states.The diffusion and distribution of Cr and the growth kinetic model of the intermetallic compound Zr-Cr-(Fe)layer were concluded,and the adverse effects of interfacial diffusion on the structural properties of the coating were summarized.ZrCr2 or Zr(Cr,Fe)2 interlayer is formed at the interface through Cr-Zr diffusion reaction.The growth of the intermediate layer is related to the manufacturing technology and roughly follows the diffusion-controlled parabolic law.The cold spray process removes the initial oxide film from the substrate and allows for faster growth compared to magnetron sputtering.Strong interdiffusion of elements at the interface can adversely affect the performance and microstructure of the coating,thus reducing its service life.The formation of the brittle interlayer at the interface accelerates the consumption of the protective Cr element and trends to become a path for crack propagation.The diffusion of Zr along Cr grain boundaries creates fast diffusion pathways for oxygen and promotes coating failure.The difference in Cr and Zr diffusion fluxe

关 键 词：燃料包壳 Cr涂层 界面 元素扩散 阻挡层 

分 类 号：TG174.4[金属学及工艺—金属表面处理]