耐核辐照损伤的SiC/SiC复合材料连接及抗辐照机理研究

SiC/SiC复合材料是针对下一代核裂变反应堆和聚变反应堆对更高事故裕度需求的关键包壳材料之一，然而SiC/SiC的连接及接头抗辐照损伤研究刚刚起步。本项目拟采用SiO2-Al2O3-Re2O3（Re：Y、Yb、Nd、Lu）、CaO-Al2O3两种体系的玻璃-陶瓷焊料；Ti3SiC2、Ti+Si、TiC+Si三个Ti-Si-C体系焊料连接SiC/SiC，并在以上焊料体系中加入SiC和Si3N4粉末构成复合焊料，利用试验和理论计算方法，系统研究焊料成分和连接参数对接头组织和性能的影响规律。利用原位离子辐照透射电镜和高压电镜原位电子辐照，观察连接样品的抗辐照行为，分析接头内部构成相的辐照协同效应，结合应力场和热场计算，指导焊料成分设计，优化抗高温核辐照的焊料体系，揭示接头内构成相的有效调控机制，阐明SiC/SiC复合材料接头的抗辐照机理。为SiC/SiC包壳材料的连接提供理论指导和技术支持。

SiC/SiC composite is an important fuel cladding material with require high radiation tolerant for the next generation fission reactor and fusion reactor. However, the research of robust joining and mechanism of nuclear irradiation resistance of the joint of the SiC/SiC composite is not enough. Two systems of glass solder (SiO2-Al2O3-Re2O3（Re：Y、Yb、Nd、Lu）and CaO-Al2O3) and three systems of solder (Ti3SiC2, Ti+Si and TiC+Si) are designed to join SiC/SiC composite. The addition of SiC and Si3N4 powders into the solder to form the composite solder will also be investigated. The effect of solder compositions, joining environment and parameters on the microstructure and mechanical properties of the joints will be studied systematically through experiments and simulations, and the joining mechanism of SiC/SiC composite will be revealed. The irradiation resistance of the joints will be researched using In-situ Ion Irradiation Transmission Electron Microscope (I3-TEM) and Ultra-High Voltage Electron Microscope (HVEM). The irradiation synergistic effect of different phases in the joints will also be studied. Combined with the finite element model of temperature and stress fields, the composition of solders can be optimized, and finally solders with good high temperature resistance and irradiation resistance will be obtained. The results will provide theoretical guidance and technical assistance for the joining technology of SiC/SiC cladding materials.