Vacuum brazing of Zircaloy-4 and stainless steel using Ag-Cu-Ti brazing filler metal

Zirconium-based dissolver vessels containing highly radioactive and concentrated corrosive nitric acid solution needs to be joined to the rest of fuel reprocessing plant made of stainless steel(SS), which demands high integrity and corrosion resistant dissimilar joints. Vacuum brazing joining process was proposed in the present work to join zircaloy-4 and 1Cr18Ni9Ti SS since fusion welding processes produce brittle intermetallic precipitates at the interface which reduce the mechanical strength as well as the corrosion resistance of the joint. It is observed that Ag-Cu eutectic phase structure was formed in the brazing seam, a reaction layer exhibited in the interface between zircaloy-4/Ag-Cu-Ti. The concentration of the dendrites increases with an increase in bonding temperature. The width of the reaction layer increases with the increase of the brazing temperature and holding time.