Cracking during solidification of diffusion bonded Inconel 625 in the presence of Zircaloy-4 interlayer

Diffusion bonded specimens of Inconel 625 in the presence of Zircaloy-4 interlayer have been investigated using scanning electron microscope (SEM) having energy dispersive system (EDS) as an attachment. Cracking is observed in the center of the diffusion zone (DZ) in both the samples bonded at 1050 and 1100 °C. The bonding of Inconel 625 in the presence of Zircaloy-4 occurs due to the formation of eutectic. The phases in the DZ have been investigated. Hardness values are high at Cr, Cr–Mo rich layers as well as in the start of the DZ and low at the center of the DZ. Variation in the hardness profile in the center region of both the samples bonded at 1050 and 1100 °C is observed but variation is large in the case of sample bonded at 1050 °C.