Ag元素对真空扩散焊Cu/Al界面组织及性能的影响

Effects of Ag on Interface Microstructure and Properties of Cu/Al Vacuum Diffusion Welding

通过添加不同厚度的Ag中间层,采用真空扩散焊工艺进行Cu/Al异质金属连接。利用扫描电镜(SEM)及能谱仪(EDS)对界面的元素分布及相组成进行分析,采用剪切试验及电化学腐蚀能测试对异质复合接头力学及耐腐蚀性能进行了分析。结果表明,Ag中间层可以有效抑制Al和Cu界面生成脆性金属间化合物相,Ag以较快的方式扩散进入Al基体的晶界中。界面上生成宽度较窄的Cu、Al化合物。与Cu/Al直接连接相比,添加Ag箔的界面电化学腐蚀电位有明显提升,表明Ag元素的添加有效改善了Cu/Al接触界面的耐腐蚀性能。

By adding the Ag intermediate layer with different thicknesses, the vacuum diffusion welding was used to connect the Cu/Al dissimilar metals. The element distribution and phase composition of the interface were analyzed by scanning electron microscopy （SEM） and energy spectrometer （EDS）. The shear strength and corrosion resistance of the joints were tested by shear test and electro-chemical corrosion test. The results show that Ag interlayer can effectively inhibit the formation of brittle intermetallic compound phase at the interface between Al and Cu. Ag diffuses fastly into the grain boundary of A1 matrix. The Cu and Al compound with narrow width forms at the interface. Compared with Cu/Al direct connection, the electrochemical corrosion potential of the interface by adding Ag foil significantly increases, which shows that the addition of Ag element can effectively improve the corrosion resistance of the Cu/Al interface.