Formation mechanism of intermetallic components during dissimilar diffusion bonding of IN718/BNi-2/AISI 316 L by TLP process

In this research, microstructure and intermetallic components of IN 718/BNi-2/316L joint were studied. Dissimilar bonding was carried out at a temperature of 1050 C-degrees and, bonding time varied at 30 and 45min in a vacuum furnace under an approximate pressure of 10(-5) mbar. After TLP joining, samples were analyzed by energy dispersive x-ray spectroscopy (EDX) and X-Ray diffraction (XRD) methods. After microscopic studies on bonding region and diffusion affected zone (DAZ), it was observed that both types of TLP bonding morphology isothermal and athermal/eutectic are rich in B, Ni, Cr and Fe. On the other hand, the process of intermetallic components formation using ternary phase diagram was studied. Results show that borides components in 316L - DAZ and IN 718 -DAZ regions were CrB and Nb2Ni21B6, respectively. Additionally, it was observed that intermetallic components texture evolution on the DAZ region was different for In718 and 316L alloys.