Vacuum brazing of active metallized Al₂O₃ ceramic to 5005 aluminum alloy

The Al₂O₃ ceramic were metallized with the Ag-Cu-Ti powder, and then used Al-Si filler to braze Al₂O₃ ceramic and 5005 aluminum alloy. The influence of brazing temperature on the interfacial structures and shear strength has been researched. It was shown that the typical interface structure of the joints was 5005 aluminum alloy/α-Al+θ-Al₂Cu+ξ-Ag₂Al/ξ-Ag₂Al+θ-Al₂Cu+Al₃Ti/Ti₃Cu₃O/Al₂O₃ ceramic. During the brazing, Al-Si-Mg filler reacted with Ti and 5005 aluminum alloy, which made the joints of Al₂O₃ ceramic and 5005 aluminum alloy. With the increased of brazing temperature, the thickness of the Ti₃Cu₃O reaction layer adjacented to the Al₂O₃ ceramic was thinned. Besides, more Ag reacted with Cu and Al, and the amount of ξ-Ag₂Al+θ-Al₂Cu increased. And the shear strength of the joints increased firstly and then decreased with the increase of brazing temperature. The maximum shear strength of joints was 15 MPa when vacuum brazing was performed at 610 °C for 5 min.