Abstract: Based on the empirical electron theory (EET) of solids and molecules, the glide energies of two structures (D03-type and B2-type) of Fe3Al were calculated firstly. The result shows the glide energy of B2-type Fe3Al is less than that of D03-type Fe3Al. When the less work is done, the B2-type Fe3Al can preferentially slip. It predicts B2 structure has better ductility than D03 structure, then Fe3Al is processed by order degree interception, the results indicate a Fe3Al with an imperfectly ordered B2 structure after orderdegree intercepted has improved machinability properties deeply, the hardness and compressive strength decrease simultaneously. According to the study, relationships of valence electron structures of two structures and mechanical properties have been set up.The results obtained well conform to the experimental data.

Key words: Based on the empirical electron theory (EET) of solids and molecules, the glide energies of two structures (D03-type and B2-type) of Fe3Al were calculated firstly. The result shows the glide energy of B2-type Fe3Al is less than that of D03-type Fe3Al. When the less work is done, the B2-type Fe3Al can preferentially slip. It predicts B2 structure has better ductility than D03 structure, then Fe3Al is processed by order degree interception, the results indicate a Fe3Al with an imperfectly ordered B2 structure after orderdegree intercepted has improved machinability properties deeply, the hardness and compressive strength decrease simultaneously. According to the study, relationships of valence electron structures of two structures and mechanical properties have been set up.The results obtained well conform to the experimental data.