Transient liquid phase bonding of Inconel 617 superalloy: effect of filler metal type and bonding time

Transient liquid phase (TLP) bonding has enormous potential to repair cracks in the gas turbine hot section parts that are made of Ni-based alloys. The experiments were carried out by BNi-1 and BNi-2 filler metals in a vacuum furnace at the bonding times of 45 and 300 min. The shear strength, microhardness, microstructure, and homogeneity of chemical composition during TLP bonding of Inconel 617 superalloy, which is the base metal, were evaluated. The shear strength of about 620 MPa was obtained using the BNi-1 filler metal. Hence, the BNi-1 filler metal and the bonding time of 300 min are recommended for repair of hot section components of a gas turbine. The gap size is an important parameter on the diffusion especially at the lower bonding times but the preliminary difference in the chemical composition may play an important role at the longer bonding times. The results show that the type of filler metal is an important parameter in this process.