Joining of stainless steel 304L with Zircaloy-4 by diffusion bonding technique using Ni and Ti interlayers

A methodology, based on diffusion bonding has been developed, for joining stainless steel (SS) type 304L and Zircaloy-4 using Ni and Ti interlayers. Diffusion bonding was performed in the range of 800 degrees C-900 degrees C under vacuum for different time intervals varying between 30 and 90 min. The bonding parameters were optimized at bonding temperature of 850 degrees C for 60 min duration, when the maximum shear strength of 209 MPa was obtained. The SS 304L/Zircaloy-4 joint interfaces showed the formation of different intermetallics like NiZr2, NiZr, Ni3Ti, NiTi and NiTiZr in layered morphology. The interface of the joint bonded at 900 degrees C showed the formation of Ni-Zr type intermetallics, while those of the joints bonded at 800 degrees C and 850 degrees C showed the presence of Ni-Ti type intermetallics. The phases present on the both SS and Zircaloy fracture surfaces were identified as NiTiZr and NiZr2 for bonding conditions 850 degrees C-60 min and 900 degrees C-30 min, respectively.