Properties of Iron-Aluminum Alloys with Aluminum Contents Greater than 30%.

A study was made of the mechanical, magnetic, and structural properties of Fe-Al alloys containing from 35. 0 to 52. 8 wt% Al plus microadditions of cobalt, carbon, and chromium. The investigated alloys are found to possess in the range from 35. 8 to 45. 3 wt% Al a two-phase structure consisting of an alpha -phase and an intermetallic phase FeAl//2. The impact strength of these alloys is close to that of cast irons and decreases with an increase in the aluminum content. An increase in the aluminum content from 35. 8 to 46. 8 wt% causes a decrease in the hardness of the alloys from 824 HV to 519 HV. The maximum hardness (882 HV) is observed in an alloy containing 39. 6 wt% Al and 0. 02 wt% Cr. The investigated alloys show a fissile transgranular transformation, which is unaffected by the microadditives employed. Finally, these alloys possess very weak magnetic properties.