A new mechanism of dynamic phase transformations in an isothermal forged beta-gamma intermetallic alloy

Abstract

A new mechanism of dynamic phase transformations of α 2 ↔ γ in an isothermally forged -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 α2 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.