Physical simulation of hot deformation of TiAl based alloy

Abstract

In order to establish a model between the grain size and the process parameters, the hot deformation behaviors of Ti-49.5Al alloy was investigated by isothermal compressive tests at temperatures ranging from 800 to 1 100 °C with strain rates of 10⁻³∓10⁻¹ s⁻¹. Within this range, the deformation behavior obeys the power law relationship, which can be described using the kinetic rate equation. The stress exponent, n, has a value of about 5.0, and the apparent activation energy is about 320 J/mol, which fits well with the value estimated in previous investigations. The results show that, the dependence of flow stress on the recrystallized grain size can be expressed by the equation: σ=K₁d_rex^−0.56. The relationship between the deformed microstructure and the process control parameter can be expressed by the formula: 1gd_rex=−0.281 1gZ + 3.9081.

Keywords

hot deformation / TiAl based alloy / microstructure refining / Zener-Hollomon parameter

References

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