【作者】 赵健； 徐志彤； 刘马林； 于浩； 常佳兴； 邵友林； 刘兵； 刘荣正；

【Author】 ZHAO Jian;XU Zhi-tong;LIU Ma-lin;YU Hao;CHANG Jia-xing;SHAO You-lin;LIU Bing;LIU Rong-zheng;Institute of Nuclear Energy and New Energy Technology of Tsinghua University;

【机构】 清华大学核能与新能源技术研究院；

【摘要】 SiC陶瓷是全陶瓷微封装燃料中重要的基体材料,具有熔点高、与水蒸气反应活性低、高温力学性能优异和中子吸收截面小等优点。然而SiC陶瓷材料固有的脆性问题也是SiC基新型燃料元件必须面对和解决的关键核心问题。层状复合增韧即通过叠层手段制备以SiC和石墨（C）相间堆叠的SiC/C层状复合陶瓷,是SiC陶瓷有效的增韧方式。本课题采用流化床化学气相沉积法（FB-CVD）制备SiC/C复合包覆层,并以复合包覆层为粉体、Al为烧结助剂,通过放电等离子烧结（SPS）制备SiC/C层状复合陶瓷。相比于传统的流延法制备的层状复合材料,本课题制备的SiC/C层状复合陶瓷具有更好的各向同性。在1800℃、50 MPa的烧结温度和压力下制备的SiC/C层状复合陶瓷的弯曲强度和断裂韧性分别为385 MPa和7.42 MPa·m^1/2。更多还原

【Abstract】 SiC ceramics are important matrix materials in fully ceramic microencapsulated fuels,with advantages such as high melting point,low reactivity with water vapor,excellent high-temperature mechanical properties,and small neutron absorption cross-section.However,the inherent brittleness of SiC ceramics is also a key issue that SiC based fuel elements must face and solve.Layered composite toughening refers to the preparation of SiC/C layered composite ceramics stacked between SiC and graphite（C） through layering,which is an effective toughening method for SiC ceramics.This project uses fluidized bed chemical vapor deposition（FB-CVD） to prepare SiC/C laminated coating layer,and uses the composite coating layer as the sintering powder and Al as the sintering aid to prepare SiC/C laminated ceramics via spark plasma sintering（SPS）.Compared to the laminated materials prepared by traditional tape casting method, the SiC/C laminated ceramics prepared in this study have better isotropy.The bending strength and fracture toughness of SiC/C laminated ceramics prepared at 1800℃ and 50 MPa are 385 MPa and 7.42 MPa·m^1/2,respectively.更多还原