An Investigation on Vacuum Brazing of Dissimilar Nonferrous Metals of Cu and Al

摘要

The writer successfully obtained brazed Cu-Al joint by using vacuum brazing method, and also conducted an analysis for the microstructure morphology of the joint. The result shows that: The interface of the brazed Cu-Al joint includes three parts-the transition area on the Cu side, the central brazing seam area and the transition area on the Al side. Formed between the brazing seam area and the Cu substrate are the Cu_3Al_2 and CuAl_2 layers, and the average width of the transition area of Cu_3Al_2 is 12 urn while that of CuAl_2 8 μm. The brazing seam area is mainly composed of a-Al solid solution, Cu_3Al_2 and CuAl_2 metal compounds, in addition, the S-Cu_(15)Si_4 phase, the Al-Si phase and CuZn_2 phase are also formed. These phases present themselves in the state of acicular compounds, which are dispersed in the brazing seam area.