Process of vacuum brazing 5005 aluminum alloy to 4J34 Kovar alloy

Vacuum brazing of 5005 aluminum alloy and 4J34 Kovar was carried out with Al-Si-Mg filler foil as braze alloy. Various brazing heating cycles were carried out to study the effects of brazing parameters on the joint interface and mechanical properties. The results show that the shear strength of the joints increases firstly, and then decreases with increasing brazing temperature and holding time. According to the mechanical property tests, the joints brazed at 580℃ for 15 min obtain the maximum shear strength of 81 MPa, and the typical interface structure of the joints is 4J34 Kovar/FeAl/FeAl₃/Fe_mAl_n+α (Al)/5005 aluminum alloy from 4J34 Kovar to 5005 aluminum alloy side. The fracture form of the joints is mainly affected by brazing temperature. When the brazing temperature is low, the joints fracture on the oxide layer and aluminum alloy. When the temperature is high, the joints fracture on Fe_mAl_n+α (Al) layer.