Abstract:According to the Average Lattice and Atom Models of the Empirical Electron Theory of Solids and Molecules(EET), effects of interstitial impurities on valence electron structures and phase transformation of Ti-Al alloys are analyzed, and descendant degree of bond energy, melting point and liquidus temperatures affected by interstitial impurities are calculated by the bond energy formula of the EET, and then the main experimental results which are not confirmed about phase transformation in Ti-Al alloys are explained. The results are that, because of the effects of interstitial impurities, atom states increase, bond structures are seriously anisotropic,β→αtransformation is hindered, and the phase transformation in an intermediate content is very complex. Also, the melting point and liquidus temperatures decrease, and average decreased degree is estimated through approximation by the EET.

Key words: Ti-Al alloys　phase transformation　valence electron structure　interstitial impurities