The wetting and interface reaction mechanism of Ag-Cu-O brazes on BaCo0.7Fe0.2Nb0.1 O3-δ oxygen-permeable membrane ceramic

The wetting and interface reaction mechanism of Ag-Cu-O brazes on BaCo0.7Fe0.2Nb0.1 O3-δ (BCFNO) oxygen-permeable membrane ceramic were investigated by the sessile drop wetting experiment and SEM/EDS test. The results indicate that the wetting of Ag-Cu-O brazes on BCFNO follow the wetting mechanism of interface reaction, with the Cu content and temperature increased, wetting angle rapid decreased. When the content of Cu was 3.3mol%, in BCFNO side at the interface a layer of reactive layer was generated. The existence of reactive layer reduced the liquid-solid interfacial energies, then improved the wettability of interface and enhanced the mutual metallurgy effect. Reactive layer are caused by the interface reaction (CuOx+BaCoFeNbO&rarrBa-Cu-O+Co-Cu-O) occurs in the interface. The complex oxide Ba-Cu-O, Co-Cu-O in the grain boundary of BCFNO matrix show island shape distributed.