Abstract: Phase structure characteristics near the interface of Fe3Al/Q235 diffusion bonding are investigated by means of X ray diffraction (XRD), transmission electronic microscope (TEM) and electron diffraction, etc. The test results indicated that obviously a diffusion transition zone forms near the interface of Fe3Al/Q235 under the condition of heating temperature 1050-1100oC, holding time 60 min and pressure 9.8 MPa, which indicated that the diffusion interface of Fe3Al/Q235 was combined well. The diffusion transition zone consisted of Fe3Al and α-Fe(Al) solid solution. Microhardness near the diffusion transition zone was HM 480-540. There was not brittle phase of high hardness in the interface transition zone. This is favorable to enhance toughness of Fe3Al/Q235 diffusion joint.

Key words: Fe3Al intermetallic compound, Diffusion bonding, Interface, Phase structure