纤维增强SiC复合材料在辐照条件下的界面损伤研究

项目名称： 纤维增强SiC复合材料在辐照条件下的界面损伤研究

项目编号： No.11505037

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 王庆宇

作者单位： 哈尔滨工程大学

项目金额： 23万元

中文摘要： SiC 纤维增强SiC 复合材料是一种重要的先进反应堆候选结构材料，它同时具有良好的化学惰性、中子惰性和高温力学性能；以这种材料制成的燃料包壳可以显著提高燃耗深度和反应堆的可靠性和经济性。然而在中子辐照场下，纤维和基体界面受辐照后有可能形成孔洞或界面混合，使界面结合强度发生改变，从而影响材料的宏观力学性质和设计功能，严重威胁反应堆的安全运行。本项目拟采用离子辐照模拟反应堆中子辐照，在材料表层制备出等效的辐照损伤层，结合实验研究与理论分析，系统地研究纤维/基体界面在辐照条件下尤其是高辐照剂量下（200dpa）的损伤行为。拟采用显微组织分析、FIB技术和纳米力学方法，探讨界面组织损伤和力学性能之间的内在联系。采用分子动力学方法模拟界面的微观行为和性质，提供原子尺度的信息，并与实验结果结合，深入开展纤维/基体界面辐照损伤机理研究。

中文关键词： 辐照损伤；分子动力学；纳米力学；核燃料包壳；SiC复合材料

英文摘要： Super-tough and ultra-high temperature resistant materials are in critical need for nuclear applications under extreme conditions where in-core materials have to withstand neutron damage and high temperature. Ceramic composites are therefore a strong option for materials development. SiC fiber-reinforced SiC matrix (SiCf/SiC) composites possess unique properties such as high specific strength, high corrosion resistance, high elastic modulus, good fracture toughness and high radiation tolerance. SiC composite fuel cladding would sustain higher burn-up, enhance the reliability and economical efficiency of the nuclear reactor. However, porosity arised from void formation and mixing effect can decrease or enhance the interface bonding strength, altering the frictional force for fiber slip. Both of the two mechanisms would alter the macro properties of the composite, such as embrittlement. This program will employ ion irradiation technic instead of reactor irradiation to systematically investigate the irradiation damage behavior of the interfacial bonding. The work includes systematic comparison studies with variables including irradiation temperatures (up to 1200 degree C), ion fluences (up to 200 displacement per atom), ion flux, and ion species (Si only vs. Si+He co-irradiation). By conducting FIB and nanomechanics, build relationships between irradiation damage and mechanical properties. Knowledge obtained from ion irradiation experiments will be quantitatively linked and compared to molecular dynamics. The final deliverables include development of prediction capability based on experimentally validated modeling results, and feedback to materials synthesis to optimizematerials performance.

英文关键词： irradiation damage;molecular dynamics;nano-mechanics;nuclear fuel cladding;SiC composite materials