Flow Characteristics Analysis of TC18 Titanium Alloy during Hot Deformation Based on Phase Transformation

Abstract

An accurate flow stress model was established by considering the parameters of strain rate, strain and temperature as well as β → α+β phase transformation in order to develop the plastic forming theory of TC18 titanium alloy. Firstly, the phase transition kinetics of TC18 titanium alloy during isothermal and continuous cooling at 1 073 and 1 273 K was studied by thermodynamic calculation, meanwhile, the relationship of volume fraction of phase transition with temperature and time was obtained. Constitutive models were calculated by investigating flow behaviors under hot compression tests with the strain rates of 0.001–1 s⁻¹ and temperatures of 973–1 223 K in the single β and α+β regions in TC18 titanium alloy, respectively. By combining the phase transformation dynamic kinetics with constitutive models, an accurate flow stress model was established, providing theoretical basis and data support for the hot forging of TC18 titanium alloy.

Keywords

constitutive modeling / TC18 titanium alloy / phase transformation / flow stress

References

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