The most principal obstacle to the development of intermetallic compounds Fe_3Al and FeAl as constructional materials is always the room temeprature (RT) embrittleo-ment. The early studies indicated that the poor RT ductility of polycrystalline Fe_3Al with DO_3 structure was due to the weakness of grain boundaries, which results in the easy intergranular fracture. It was found from the experiments in recent years The most principal obstacle to the development of intermetallic compounds Fe_3Al and FeAl as constructional materials is always the room temeprature (RT) embrittleo-ment. The early studies indicate that the poor RT ductility of polycrystalline Fe_3Al with DO_3 structure was due to the weakness of grain boundaries, which results in the easy intergranular fracture. It was found from the experiments in recent years