Stress analysis of a Fe3Al/Q235 diffusion bonded joint using finite element analysis

Fe₃Al intermetallics and Q235 steel are bonded using vacuum diffusion bonding technology. The interfacial shear strength was measured and the stress of Fe₃Al/Q235 diffusion bonded joint was analyzed using finite element analysis (FEA). The results indicate that interfacial shear strength increases from 39.9 to 112.3 MPa with the enhancement of heating temperature from 1000 to 1060°C. Also, shear fracture has more characteristics of cleavage fracture. The farther from the central axis of the interface, the larger the stress is, and the maximum stress appears on the surface of the joint. The maximum stress increases with the heating enhancement and increase of material thickness. When the thickness reaches a critical value (6 mm) and then increases, the stress increases slightly and even to a stable value.