DT4电工纯铁与QCr0.5铬青铜真空熔钎焊接头组织及力学性能  

Microstructure and mechanical properties of DT4 electrical pure iron and QCr0.5 chromium bronze vacuum welded-brazed joints

作　　者：刘德运 董廷斌 彭飞 李云月 赵明远 沈元勋 Liu Deyun;Dong Tingbin;Peng Fei;Li Yunyue;Zhao Mingyuan;Shen Yuanxun(State Key Laboratory of Advanced Brazing Filler Metals and Technology,Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd.,Zhengzhou 450001,China;AVIC Xinxiang Aviation Industry(Group)Co.,Ltd.,Xinxiang 453000,Henan,China)

机构地区：[1]郑州机械研究所有限公司新型钎焊材料与技术国家重点实验室,郑州450001 [2]新乡航空工业(集团)有限公司,河南新乡453000

出　　处：《焊接》2024年第11期33-38,共6页Welding & Joining

基　　金：国家重点基础研究发展计划(973计划)。

摘　　要：【目的】合金铁与铜合金的异种金属连接结构,能够同时利用两种金属的优异性能,具有很广泛的应用前景。该文旨在获取性能优异的铁/铜焊接接头,为其应用提供数据支撑。【方法】该文选用DT4电工纯铁与QCr0.5铬青铜作为母材,采用炉中真空熔钎焊连接DT4电工纯铁与QCr0.5铬青铜,使用光学显微镜和扫描电子显微镜对连接界面处微观组织及元素扩散进行了分析,通过接头硬度及抗剪强度对接头力学性能进行了评价。【结果】结果表明,采用炉中真空熔钎焊工艺可以获得铁/铜焊接接头,接头界面处形成一条宽约30μm的明显扩散层,扩散层为Cr的均匀扩散和Cu的非均匀扩散,Cr的扩散对DT4有强化的作用,使铁素体的强度、硬度提高,界面扩散层硬度明显高于两侧母材,有着最高的硬度,进一步增强界面处的冶金结合。【结论】接头平均抗剪强度146.2 MPa,断口断裂位置大面积发生于QCr0.5母材处,为韧性断裂模式,接头冶金结合质量良好。[Objective]Dissimilar metals connection structure between alloy iron and copper alloy can simultaneously utilize excellent properties of both metals,which has a wide range of application prospects.This paper aimed to obtain iron/copper welded-brazed joints with excellent performance and provide data support for their application.[Methods]DT4 electrical pure iron and QCr0.5 chromium bronze were selected as base material in this paper,furnace vacuum welding-brazing was used to connect DT4 electrical pure iron and QCr0.5 chromium bronze.Microstructure and element diffusion at the connection interface were analyzed by optical microscopy and scanning electron microscopy,and mechanical properties of welded-brazed joints were evaluated through hardness and shear strength of welded-brazed joints.[Results]The results showed that iron/copper welded-brazed joints could be obtained by furnace vacuum welding-brazing process.A clear diffusion layer with a width of about 30μm was formed at the interface of welded-brazed joints,which was composed of uniform diffusion of Cr and non-uniform diffusion of Cu.Diffusion of Cr had a strengthening effect on DT4,which increased strength and hardness of ferrite.Hardness of diffusion layer at the interface was significantly higher than that of base material on both sides,and it had the highest hardness and further enhanced metallurgical bonding at the interface.[Conclusion]Average shear strength of welded-brazed joints was 146.2 MPa.Fracture occurred in QCr0.5 base material,which was a ductile fracture mode.Metallurgical bonding quality of welded-brazed joints was good.

关 键 词：异种金属 熔钎焊 显微组织 力学性能 

分 类 号：TG454[金属学及工艺—焊接]