Investigation Of The Interfacial Stability Between Silver-based Alloy And Oxygen Permeable Membrane

Dense mixed conductor ceramic oxygen permeable membrane has broad application prospects such as high-temperature pure oxygen producting,membrane reforming reactor,oxygen-enriched combustion.The key to construct membrane reactors is high-temperature brazing joint between the ceramic permeable membrane and its metal support.It is vital for improving the quality and stability of the sealing structure to find out the stability and evolution of the sealing interface in the high-temperature atmosphere.So we decide to study the stability and evolution of the sealing interface between Ag-Cu braze and BCFN by simulating the woking situation.According to our study,the results are summarized for heat treatment in air and Ar as follows:interfacial reaction is premise for wetting for Ag-Cu/BCFN;the evolutions of the interfaces are similar for different Ag-Cu brazes when the samples are treated in air at 850?,the thickness of the reaction layers increases as the heat treatment time increases until it reaches to 500 h;the products Ba₂Cu₂O₅ and solid solution Co-Cu-O oxide do not change before and after heat treatment in air at 850?.And the products are BCFN,Ag and Cu₂₊₁Owhen samples are treated in Ar at 850?.Besides,there are holes and cracks in the interface reaction layer.Interfacial reaction is also premise for wetting for Ag-CuO/BCFN,and CuO_x wraps the BCFN substrate after brazing as the little reacting time.The evolution of the interfaces is similary for different Ag-CuO brazes when the samples are treated in air at 850?,the thickness of the reaction layers increases as the heat treatment time increases.And the products are Ba₂CuO₃ and solid solution Co-Cu-O oxide after heat treatment in air at 850?,the products are BCFN,Ag and Cu₂₊₁O when samples are treated in Ar.Becides,the membrane reactors are also researched.The results are summarized as follows:there are no big differences in the interface structure before and after working at 850? for 100h for the oxygen premeating reactor.But the Ba-Cu-O oxide decomposes to Cu oxide and Ba oxide.The structure of reforming reaction reactor is similar with the premeating reactor after working at 850? for 100h.And the thickness does not change after working.Within the experimental study,the two reactor do not leak and the airtightness of the sealing structure is good.