Effect of Al on microstructure and mechanical properties of IC10 joints transient-liquid-phase bonding with Al/BNi2 composite filler

IC10 alloy is a promising material for the applications of engine turbine blades. Fabricating and repairing of the turbine blades urgently need a sound joining technique for the IC10 alloy. The traditional transient liquid phase (TLP) bonding method is difficult to achieve isothermal solidification, which tends to form brittle eutectic phases. In this study, a novel Al/BNi2 composite filler was designed. This new type of composite filler facilitates the diffusion of elements to completely dissolve or disperse the brittle eutectic structure of continuous large blocks in the TLP joint, thereby improving the room-temperature mechanical properties of the joint and increasing its average shear strength by 20% to 550 MPa. Effect of Al content and bonding temperature on microstructure and mechanical strength of the IC10/Al/BNi2/IC10 joint was investigated. Microstructure evolution mechanisms of the traditional TLP bonding method (with a pure BNi2 filler) and the novel TLP bonding method (with the Al/BNi2 composite filler) were put into comparison. The TLP joint of the new filler achieved a maximum room temperature shear strength of 570 MPa (3 wt.% Al, 1100 ?, 2 h). 2026 The Authors.