Dynamic Impact Compression Mechanical Properties and Modified J-C Constitutive Model of DZ4 Superalloy

DZ4 nickel-based superalloy is primarily employed in the fabrication of critical high-temperature components such as turbine blades and working guide vanes for aero-engines. To obtain the mechanical properties of DZ4 alloy under dynamic impact compression and develop an accurate constitutive model for characterizing its dynamic mechanical behavior, dynamic impact compression tests were conducted using a split Hopkinson pressure bar (SHPB) system under temperature range of 25 ℃-900 ℃ and strain rate range of 1000 s^-1-6000 s^-1. The sensitivity of the stress-strain response of the DZ4 alloy to temperature and strain rate was discussed. A modified Johnson-Cook constitutive model was developed to effectively predict the plastic flow behavior of the DZ4 alloy. The results show that the modified J-C constitutive model accounts for the coupling effects of strain, strain rate and temperature. The model predictions exhibit a high degree of consistency with the experimental observations, with a correlation coefficient R of 0.9768 and a mean relative error (MRE) of 2.16%. It shows that the model can accurately characterize the stress response behavior of DZ4 alloy under the above test conditions.