Compression and yield characteristics of CuCrZr alloy under high-pressure and high-strain-rate loading

Abstract

CuCrZr alloy is a promising candidate for electromagnetic railgun rails owing to its combination of high strength and hardness with excellent electrical and thermal conductivity. Investigating its dynamic behavior under high-pressure (>10 GPa) and high-strain-rate (>105/s) conditions is of great significance, as it not only elucidates the material's mechanical response in extreme service environments but also informs the design and performance evaluation of rail materials. In this study, shock and ramp loading experiments were conducted using magnetically driven compression devices. Key properties of CuCrZr alloys, including its high-pressure equation of state, dynamic yield strength, and spall strength, were determined in these experiments, where the dynamic yield strength was specifically calculated by combining the self-consistent method with a long short-term memory neural network inversion approach. The results showed that the sound velocity of CuCrZr alloys under both shock and ramp loading exhibits good consistency, and the corresponding pressure–specific volume (P–V) curves are in good agreement at pressures below 20 GPa with relative deviation less than 2.23%. Under shock compression, the relation between shock wave velocity and particle velocity of CuCrZr alloys is very close to that of oxygen-free copper (OFHC), indicating that the high-pressure compression characteristics of CuCrZr alloys is similar to those of OFHC. The measured dynamic yield strength of CuCrZr alloys ranged from 375 to 691 MPa, consistently exceeding that of OFHC, with the discrepancy diminishing as pressure rises. The spall strength was found to be 1.65–1.88 GPa and increases with peak loading pressure, significantly higher than that of OFHC (1.0–1.5 GPa). This study provides critical experimental data for the application of CuCrZr alloy under extreme dynamic loading.