Vacuum Brazing Processes of Aluminum Foam

Butt joints of aluminum foam were made by three different brazing processes including brazing with multilayer filler metal in high vacuum of 10−3 (Pa) degree, brazing with multilayer filler metal in low vacuum of 1 (Pa) degree and brazing with monolayer filler metal in high vacuum of 10−3 (Pa) degree. The macrostructure and microstructure characteristics and bending strength of the joints were investigated and compared. The results indicate that the brazed specimen can achieve a satisfactory joint when brazed with multilayer filler metal in high vacuum. The bending strength of the joint is higher than that of the base metal. However, the bending strength of the joint is obviously lower than that of the base metal when brazed with multilayer filler metal in low vacuum, while it is slightly lower when brazed with monolayer filler metal in high vacuum.