Multicomponent Diffusion Studies in Selected High Temperature for IN718/BNi-2/316L Diffusion Couple

The phenomenology of multicomponent diffusion studies was carried out in the IN718/BNi-2/AISI 316L joined couple at bonding temperature 1050 °C for bonding time 45 min. This study has been employed for the determination of interdiffusion fluxes, zero-flux planes and chemical potential gradient for multicomponent system of IN718/BNi-2/316L. The chemical composition of phases in the diffusion zone were analyzed by energy-dispersive spectroscopy, and the mobility parameter was extracted from Thermo-Calc software, DICTRA module. Interdiffusion fluxes of individual components, e.g., Ni, Cr, Fe, Si, B, Ti and Nb, were determined directly from the experimental concentration profiles and were examined in the light of diffusional interactions. The calculated flux result revealed that boron diffusion toward IN718 alloy was more than 316L alloy in the presence of other alloying elements. In addition, this observation was evaluated thermodynamically using the chemical potential gradient that was calculated for each component. The chemical potential results showed that the chemical potential gradient of boron in the presence IN718 elements was lower than chemical potential gradient of boron in the presence 316L elements.