NiTi+Ni钎料真空钎焊SiC陶瓷的微观组织及性能  

Microstructure and Properties of Vacuum Brazing SiC Ceramics with NiTi+Ni Filler

作　　者：刘自豪 颜家振[1] 李宁[1] 石浩江[1] 白冬 LIU Zihao;YAN Jiazhen;LI Ning;SHI Haojiang;BAI Dong(School of Mechanical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学机械工程学院,四川成都610065

出　　处：《热加工工艺》2023年第19期20-23,共4页Hot Working Technology

摘　　要：SiC作为潜在的下一代核反应堆包壳材料,实现其稳定可靠的连接是SiC基包壳管投入实际工程应用的重要一环。使用镍含量为55at%的NiTi粉和Ni粉混合膏状钎料(NiTi+5Ni钎料)在1350℃保温10min的工艺下实现了SiC陶瓷的连接。结果表明:焊缝界面区域组织为TiC连续反应层;中心区域基体组织为δ-Ni_(2)Si+Ni_(3)Si_(2)共析组织,其中弥散分布着大量的TiC颗粒。接头平均室温剪切强度可达125MPa,断裂位于靠近界面的SiC陶瓷内部。界面处TiC与SiC之间良好的晶格匹配度以及焊缝中心区域的TiC颗粒对接头热残余应力的缓解,提升了接头的力学性能。SiC is a potential cladding material for the next generation of nuclear reactors.The realization of its stable and reliable joining is an important part of the practical engineering application of SiC based cladding tubes.The joining of SiC ceramics was realized by using the paste brazing material mixed Ni Ti powder with Ni content of 55at% and Ni powder(NiTi+5Ni filler) at 1350 ℃ for 10 min.The results show that the microstructure of interfacial area of the brazing seam is a Ti C continuous reaction layer.The matrix structure in the central area is δ-Ni_2Si+Ni_3Si_(2) eutectoid structure,in which a large number of dispersed TiC particles are formed.The average shear strength of the joints is 125 MPa at room temperature,and the fracture is located in SiC ceramics near the interface.The good lattice matching between TiC and SiC at the interface and the TiC particles in the central area alleviate the thermal residual stress of the joint,which improves the mechanical properties of the joint.

关 键 词：钎焊 镍基钎料 SIC陶瓷 微观组织 力学性能 

分 类 号：TG454[金属学及工艺—焊接]