摘要
连续碳化硅纤维增强碳化硅复合材料(SiC_(f)/SiC)可应用于核反应堆包壳管、控制棒套筒、中间热交换器、管道等,其高可靠连接对核能安全至关重要。本文采用活性钎焊的方法连接SiC_(f)/SiC,通过分析不同温度钎焊接头微观组织、界面物相和力学性能,旨在获得高强度的连接性能。结果显示:AgCuTi钎料可以实现SiC_(f)/SiC稳定连接,并且对SiC_(f)/SiC表面打磨处理有利于提高接头的剪切强度。随着钎焊温度增加,Ti与Si和C的反应更加剧烈,当钎焊温度达到890℃时,Ti_(5)Si_(3)脆性相逐渐扩散且弥散分布于焊缝,强化相TiC成为反应层主要组元,有效改善微观组织并提升钎焊接头强度。
[Background]Continuous SiC fiber-reinforced SiC-matrix composites(SiC_(f)/SiC)can be used as the fuel cladding,control rod sheath,intermediate heat exchanger,and tube components for nuclear reactor,the reliability of its joining is very crucial to the safety of nuclear energy.[Purpose]This study aims to explore the microstructure and mechanical properties of SiC_(f)/SiC brazed joints,and optimize processing of connecting SiC_(f)/SiC with SiC_(f)/SiC using brazing method.[Methods]SiC_(f)/SiC was firstly prepared by chemical vapor infiltration(CVI)method,and active brazing method was used to join SiC_(f)/SiC under 850℃,870℃,and 890℃with Ag-26.77Cu-4.4Ti(wt.%)filler metal.Then,the microstructure and interfacial phase of the brazed joint under different temperatures were analyzed for a high joining performance using optical microscopy(OM),scanning electron microscope(SEM),and energy dispersive spectrometer(EDS).The mechanical properties of the brazed joint were analyzed using thermal simulated test machine.[Results&Conclusions]Observation results indicate that AgCuTi filler realizes stable joining for SiC_(f)/SiC,and the surface smoothing of SiC_(f)/SiC is beneficial to improve the shear strength of the joint.The reaction between Ti,Si,and C becomes more intense with the increase of the brazing temperature.When the brazing temperature reaches 890℃,the brittle phase of Ti_(5)Si_(3)gradually diffuses and disperses to the brazing seam,and the reinforced phase TiC becomes the main component of reaction layer,which effectively improves the microstructure and significantly increases the strength of the SiC_(f)/SiC brazed joint.
作者
张宝亮
张宏强
涂蒙河
张瑜
郭伟
ZHANG Baoliang;ZHANG Hongqiang;TU Menghe;ZHANG Yu;GUO Wei(China Institute of Atomic Energy,Beijing 102413,China;Beihang University,Beijing 100083,China;Jiangxi Research Institute,Beihang University,Nanchang 330096,China)
出处
《核技术》
北大核心
2025年第5期177-185,共9页
Nuclear Techniques
基金
中国原子能科学研究院反应堆工程技术研究部第二届创新基金项目(No.196620)
国防科技工业核材料技术创新中心基金(No.ICNMT-2018-YZ-02)
江西省自然科学基金面上项目(No.20232BAB204051)资助。
