A Comparative Study on Arrhenius and Johnson–Cook Constitutive Models for High-Temperature Deformation of Ti₂AlNb-Based Alloys

In order to thoroughly understand the quantitative relationships between the flow stress and deformation conditions for Ti2AlNb-based alloys at elevated temperatures, the Arrhenius and Johnson⁻Cook constitutive models are analyzed and identified on the basis of the uniaxial tensile tests. The Johnson⁻Cook model is modified so that the referenced temperature range can be randomly adjusted. By experimental verification, the Arrhenius model (including the Backofen model) is suitable for the deformation at relatively low strain-rate deformation, such as the superplastic forming, and the modified J⁻C model is applicable for the deformation within a wide range of strain rates. For deformation at high temperatures, the constitutive model enables a more precise description of the effect of strain on the flow stress through introducing as train-softening factor exp(sε)