The effect of active elements on the microstructure and properties of graphite and copper-brazed joints  

作　　者：Jiebing Yu Ling Kang Jiaxin Chen Xiaofang Zhang Xu Shen Guangyuan Wang Yongji Yu Lei Liu 

机构地区：[1]Institute of High Energy Physics,Chinese Academy of Sciences,Beijing,100049,China [2]Spallation Neutron Source Science Center,Dongguan,523803,China [3]University of Chinese Academy of Sciences,Beijing,100049,China [4]Songshan Lake Materials Laboratory(SLAB),Dongguan,523803,China [5]Institute of Plasma Physics,Chinese Academy of Sciences,Hefei,230031,China

出　　处：《Radiation Detection Technology and Methods》2024年第4期1619-1625,共7页辐射探测技术与方法(英文)

基　　金：supported by the National Natural Science Foundation of China(grant Nos.11975253,12105296,and 12105308);Guangdong Provincial Key Laboratory of Extreme Conditions(2023B1212010002).

摘　　要：Purpose To obtain better properties of joints of graphite/Cu brazing,brazing of graphite to oxygen-free copper with different coating has been employed.Methods Graphite is brazed to copper with surface coatings containing Cr,Ni or no element at 860℃ for 10 min.Results The shear strength of all joints exceeds 20 MPa.In addition to the interaction between the Ti element in the filler and the C element leading to the formation of TiC,the coating materials Cr and Ni also form Cr_(7)C_(3)and Ni_(3)C,respectively.Compared to the Cr-coated and no-coated brazed samples,the filler is distributed more evenly in the Ni-plated brazed sample.TEM diffraction patterns have been utilized to calibrate the granular metal phase forming at the brazing filler metal boundary,revealing its composition Ti(Cu,Ni)_(2).The thermal conductivity of the brazed samples has been tested at different temperatures;the Cr-coated samples show significantly lower thermal conductivity than the uncoated samples.Conversely,the thermal conductivity of the Ni-coated samples is significantly higher than that of the uncoated samples.Conclusion Graphite and copper with different coatings can be successfully joined by using AgCuTi at 860℃ for 10 min.The graphite/Cu joint with Ni coating achieves better thermal conductivity with a more even distribution of the filler.

关 键 词：Graphite/copper brazing AgCuTi filler Interfacial microstructure Ti(Cu Ni)_(2) 

分 类 号：TG1[金属学及工艺—金属学]