Effects of Transient Liquid Phase Bonding Time on Microstructure, Mechanical and Corrosion Properties During Bonding of Inconel 617/AISI 310 Stainless Steel

In this study, effects of bonding time on microstructure, mechanical properties and corrosion resistance of transient liquid phase bonded Inconel 617 and AISI 310 alloys using a BNi-2 interlayer were investigated. TLP bonding was conducted at 1040 °C in a vacuum furnace and for bonding times of 15, 45 and 90 minutes. Then, microstructure, shear strength, fractured surface, hardness and corrosion resistance of the joints and the base metals were studied. The result showed that thickness of the diffusion affected zone increased with the bonding time. The optimal mechanical properties were achieved at bonding time of 45 minutes. This appeared to be due to completion of the isothermal solidification by this time. The maximum shear strength and hardness at the bonding time of 45 minutes were 618 MPa and 308 Vickers, respectively. Also, the number of intermetallic compounds formed increased resulting in a decrease in the shear strength of the joints. EIS and polarization corrosion tests on joints and base metals showed the highest corrosion resistance of the TLP-bonded sample at 45 minutes. At short bonding times, ASZ and ISZ acted as cathode and anode, respectively, causing pitting corrosion which is worse in the Cr and Mo poor zones.