Research on the constitutive mathematical model of pure Cu under room temperature to medium temperature range (25–200°C) compression deformation

Abstract This paper focuses on the compression deformation behavior of pure Cu in the room temperature to medium temperature range (25–200°C). Based on the true stress–true strain curves obtained from experiments, a comparative analysis of several typical constitutive models was conducted. The results show that the single Swift model can well describe the initial work hardening, while the Voce model is suitable for the saturation stage in the middle and later periods. However, both models have difficulty maintaining high accuracy over the entire strain range. The Johnson–Cook model has insufficient temperature sensitivity in the room temperature to medium temperature range and has a relatively high overall prediction error. In contrast, the three-segment combined model of Swift-Voce-Power function achieves the highest fitting accuracy at all three temperatures (AARE approximately 0.8%–1.2%, R 2 > 0.99), and can accurately reproduce the complete flow curve. The research indicates that this combined model is more suitable for the room temperature to medium temperature plastic deformation process of pure Cu, providing a reliable constitutive basis for numerical simulation and process design.