Diffusion bonding of iron aluminide Fe72Al28 using a pure iron interlayer

Vacuum diffusion joining of Fe72Al28 alloy with an iron interlayer was carried out at 1100 °C for different times under 3.2 MPa. SEM-EDS studies indicated major diffusion of aluminium atoms from the Fe72Al28 matrix to the pure iron interlayer giving almost the same aluminium content as in the matrix. B2-FeAl based phase was identified by SEM-EDS and X-ray diffraction studies at the weldment and on the fracture surfaces of all samples investigated. Good bonding was achieved with maximum shear strength of 396 MPa which is 86 % of the parent material shear strength for a sample welded for 4 h.