| 摘要: |
| 金属 Cr 涂层是事故容错燃料(ATF)包壳候选涂层之一，在各方面具有优异的性能。在实际工况下，包壳管会受到环向外压力的作用而导致涂层破裂，研究锆合金 Cr 涂层膜基界面裂纹萌生和扩展行为很有意义。使用多弧离子镀技术在锆合金基体表面制备 Cr 涂层，利用电子力学试验机对锆合金 Cr 涂层包壳管进行不同变形量的环向压缩试验。采用扫描电子显微镜(SEM)、 能谱仪(EDX)、XRD 和纳米压痕仪等测试设备对锆合金 Cr 涂层试样的微观组织进行表征，研究并分析 Cr 涂层表截面裂纹的微观行为。结果表明，试样的变形分为弹性变形-裂纹萌生阶段和塑性变形-裂纹扩展阶段两个阶段，发现锆合金 Cr 试样界面裂纹的产生有两种形式：① 裂纹从膜基界面处萌生，原因是 Cr 涂层和锆合金基体材料的不同使得膜基界面发生涂层应力集中；② 表面萌生裂纹，由于 Cr 涂层存在微缺陷。没有发现涂层的剥落现象，说明其界面结合性能较佳。采用多个变形量研究锆合金 Cr 涂层包壳管膜基界面裂纹的萌生与扩展过程，为 ATF 包壳涂层结构完整性和稳定性提供试验依据。 |
| 关键词: 锆合金 Cr 涂层 环向压缩 变形量 裂纹扩展 |
| DOI：10.11933/j.issn.1007-9289.20210729001 |
| 分类号:TG156;TB114 |
| 基金项目:国家自然科学基金(U1867201，U2067221)和四川省科技计划(2022JDJQ0019)资助项目 |
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| Crack Behavior of Cr Coating Zircaloy Cladding Tubes under Ring Compression |
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Yue Yanan1, Chen Huan2, Yu Shijia1, Zhou Teng1, Zhang Ruiqian2, Cai Zhenbing1
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1.Tribology Research Institute, Southwest Jiaotong University, Chengdu 610031 , China;2.Key Laboratory of Reactor Fuel and Materials, Nuclear Power Institute of China, Chengdu 610213 , China
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| Abstract: |
| Metal Cr coating is one of the candidate coatings for accident tolerant fuel (ATF) cladding, with excellent performance in all aspects. Under actual working conditions, the cladding tube will be subjected to the outward pressure of the ring to cause the coating to rupture. Therefore, it is necessary to study the crack initiation and propagation behavior of the zirconium alloy Cr coating film-based interface. Cr coating is prepared on the surface of the zirconium alloy substrate using multi-arc ion plating technology. The ring compression tests of zirconium alloy Cr coating cladding tubes with different deformations are carried out by using electronic mechanics testing machine. Scanning electron microscopy (SEM), Energy-dispersion x-ray spectroscopy (EDX), XRD and nanoindentation, and other testing equipment are used to characterize the microstructure of Cr coating samples. The microstructure behavior of the Cr coating surface and cross-section crack is studied and analyzed. The results show that the deformation of the specimen is divided into two stages: elastic deformation-crack initiation stage and plastic deformation-crack propagation stage. It is found that there are two forms of cracks at the interface of the zirconium alloy Cr coating samples: 1) Cracks originate from the coating-substrate interface because the difference between the Cr coating and the zirconium alloy base material causes stress concentration at the coating-substrate interface; 2) Cracks initiation on the surface due to micro-defects in the Cr coating. No peeling of the coating is found in this experiment, indicating that its interface bonding performance is better. Using multiple deformations to study the initiation and propagation of cracks at the membrane base of the zirconium alloy Cr coating cladding tube provides an experimental basis for the structural integrity and stability of the ATF cladding coating. |
| Key words: zircaloy Cr coating ring compression deformation cracks propagation |
