Interfacial microstructure and mechanical properties of vacuum brazed 3003 aluminum alloy honeycomb panel

Vacuum brazing of 6063/3003/6063 sandwich aluminum honeycomb panel was carried out with 4004 brazing filler metal. The effect of brazing temperature on microstructure and mechanical properties of brazed interface was studied. The results showed that microstructure of the brazed interface of 6063/3003/6063 honeycomb plate was sensitive to brazing temperature, and good metallurgical bonding could be formed at 580 ～ 595 ℃ ． Microstructure of brazing seam consisted of Al rich phase, AlSi eutectic phase and Al（Mn,Fe）Si phase. However, with the increase of brazing temperature, the corrosion degree of the base metal increased, and the base metal was almost completely dissolved at 595℃ ． The results of flat pressure test showed that the bending deformation of honeycomb core aluminum foil led to unstable collapse, the fracture occurred in the middle of honeycomb core during flat tension test, which indicated that the strength of brazed interface was high, and the fracture did not occur at the brazed joint.