Infrared brazing Fe3Al intermetallics using the Cu filler metal

Microstructural evolution and bonding strength of infrared brazed Fe3Al intermetallics using Cu braze foil are investigated. The matrix of β1′ martensite and Cu phase with Fe3Al precipitates is identified from the brazed zone. The amounts of β1′ martensite and Cu phase in the brazed zone are related to shear strength and fractograph of the joint. With increasing the brazing time, fractographs of joints are changed from dimple dominated fracture of Cu phase to cleavage dominated fracture of β1′ martensite due to higher Al content in the brazed zone. The highest shear strength of 291 MPa is obtained from the specimen infrared brazed at 1100 °C for 300 s featured with quasi-cleavage fracture.