| In this paper, the microstructure and property of Fe-Al intermetallic compounds were studied. The Fe-Al alloy was prepared by vacuum arc remelting with following compositions: Fe-5Al, Fe-10.8Al, Fe-15.8Al and Fe-24.3Al. The samples were heat treated under low temperature for 4 hour then furnace cooled to room temperature. The temperatures include 450℃, 500℃, and 550℃. Optical microscope, X-ray diffraction, DSC, SEM, impact machine and hardness machine were used to observe the microstructure and properties.The experimental results show that: the equilibrium phases of the alloy wereα(Fe), Fe3Al and FeAl under room temperature when Al varies from 5wt.% to 24.3wt.%. The microstructure is columnar crystals. It resulted in significant increase in hardness with the Al increase. It shows plasticity when the Al content is 5wt% and 10.8wt%, but brittle when the Al content is 15.8wt% and 24.3wt%.Optical micrographs revealed the presence of two phase structure in the alloy containing C element. The second phase is needle-shaped Fe3AlC0.5.in low carbon alloy, but the second phase form a continuous network in high carbon alloy. And the microstructure become to dendrites. The second phase is an along interdendritic regions. The hardness increases significantly with increasing carbon content, as long as room temperature impact properties. The order temperature is lower when C was added into the alloy.No significant change in microstructure was observed in the alloy containing silicon. But it is more brittle.No significant change in microstructure was observed in the alloy with Al content between 5wt% and 15.8wt% after heat treatment. There is no significant change in hardness after 450℃and 500℃heat treatment. But the hardness increase when the temperature is 550℃.For the24.3wt% Al alloy, the microstructure was refining in after heat treatment, the hardness decreased significantly after heat treatment. This may attribute to the diffusion of vacant and atoms.
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