A New Mechanism of Dynamic Phase Transformations in An Isothermal Forged Beta–Gamma Intermetallic Alloy

A new mechanism of dynamic phase transformations of α(2) ↔ γ in an isothermally forged γ-TiAl-based alloy that occur simultaneously during a short-term exposure at 1000 °C is identified in this study. In the heating process, γ phase significantly decreases through a phase transformation of γ → α(2), while new γ lamellae are precipitated in the interior of equiaxed grains of α(2) phase through a phase transformation of α(2) → γ. The reasons for the presence of these two inverse phase transformations α(2) ↔ γ occurring simultaneously are discussed.