在钛与钢的连接界面处,由于母材组元的相互扩散和反应,形成了TiFe和TiFe2金属间化合物,对接头性能影响很大。运用固体与分子经验电子理论,计算TiFe和TiFe2的价电子结构和共价键键能,并从价电子结构层次分析TiFe和TiFe2热稳定性和脆性。结果表明:TiFe2比TiFe具有更牢固的共价键络,因此其热稳定性更好;TiFe和TiFe2的脆性因子均小于0.08,表现为本征脆性。
TiFe and TiFe2 intermetallic compounds are formed at the interface of titanium alloy and steel because of diffusion and reaction, which influence the properties of the joints significantly. The valence electron structures of TiFe and TiFe2 were studied and their bond energies were calculated based on Yu's empirical electron theory of solids and molecules (EET). The results show that their strongest bonds are Fe-Ti bonds and FeⅡ-FeⅡ bonds, respectively, and the energies of their strongest bonds are 14.77 and 26.96 kJ/mol, respectively. TiFe2 has stronger bond nets than TiFe, which results in its better hot stability. According to their valence electron structures, TiFe and TiFe2 put up eigen-brittleness.