XRD and TEM analysis in the interface of diffusion bonding for Fe3Al/Q235 dissimilar materials

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 1050similar to1100degreesC, 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 alpha-Fe(Al) solid solution. Microhardness near the diffusion transition zone was HM 480similar to540. There was not brittle phase of high hardness in the interface transition zone. This is favorable to enhance toughness of Fe3Al/Q235 diffusion joint.