Abstract: The morphology and crystallographic orientation of(α_2+γ)lamellar structure in duplex Ti-47.5Al-2.5V intermetallic compound have been studied by means of TEM, microdiffraction as well as 180° and non-180° rotation twinning analysis.A possible atomic model of the interface was suggested.Thus,approach was made to a mechanism on complex nucleation of α_2+γ two phases along α-Ti interface,and growth of α_2/γ/γ_1/α_2 or α_2/γ/α_2/γ as fundamental structural unit.

Key words: TiAl intermetallic compound, lamellar structure, rotation twinning analysis, interface