“芯—鞘”结构强化C_(f)/SiC-Nb钎焊接头成形机理  

Forming mechanism of C_(f)/SiC-Nb brazed joints reinforced by core-sheath structure

作　　者：李国坤 杨梦颖 潘远樵 冯鑫鑫 王怡如 王泽宇 LI Guokun;YANG Mengying;PAN Yuanqiao;FENG Xinxin;WANG Yiru;WANG Zeyu(School of Materials Science and Engineering,Jiangsu University,Zhenjiang,212013,China)

机构地区：[1]江苏大学,材料科学与工程学院,镇江212013

出　　处：《焊接学报》2025年第2期80-86,共7页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(52405363);江苏省科技计划项目(BK20230531);江苏省高等学校基础科学(自然科学)研究面上项目(23KJB430008)。

摘　　要：为了解决陶瓷基复合材料与金属钎焊接头残余应力高、强度低的问题,采用中空骨架网络结构碳海绵作为中间层缓解接头应力,提高接头力学性能.在真空环境下对三聚氰胺甲醛泡沫进行快速高温碳化处理获得骨架连续、孔隙均匀的中空碳海绵,随后将其作为中间层辅助C_(f)/SiC复合材料与金属Nb进行钎焊连接.结果表明,在850℃/10 min的工艺参数,Ag-27Cu-3.5Ti钎料对碳海绵中空腔体填充饱满,并与碳海绵骨架反应形成了TiC包覆钎料合金的“芯—鞘”结构.当碳海绵中间层厚度达到2.0 mm时接头强度达到最高值112.6 MPa,相较于无中间层直接钎焊接头提高了56%,这得益于“芯—鞘”结构对接头的多重协同强化效应.In order to address the issues of high residual stress and low strength in the brazed joints between ceramic-matrix composites and metals,a hollow-skeleton network-structured carbon sponge was used as an interlayer to relieve the joint stress and improve the mechanical properties of the joint.The melamine-formaldehyde foam was subjected to rapid high-temperature carbonization treatment in a vacuum environment to obtain a hollow carbon sponge with continuous skeletons and uniform pores.Subsequently,it was used as an interlayer to assist in the brazing process between C_(f)/SiC composites and Nb.The results show that under the brazing parameter of 850℃/10 min,the Ag-27Cu-3.5Ti filler metal fully filled the hollow space of the carbon sponge and reacted with the carbon sponge skeleton to form a core-sheath structure in which the filler metal alloy was coated with TiC.When using the thickness of the carbon sponge interlayer as 2.0 mm,the joint strength reached a maximum value of 112.6 MPa,which is 56%higher than that of the direct brazed joint without an interlayer.This is attributed to the multiple synergistic strengthening effects of the core-sheath structure on the joint.

关 键 词：钎焊 残余应力 碳海绵 力学性能 “芯—鞘”结构 

分 类 号：TG425[金属学及工艺—焊接]