Multiscale analysis of Al4Cu9 intermetallic compounds on shock Hugoniot of Al-Cu composites: Experiments and simulations

Analyzing material response under high-pressure requires precise shock Hugoniot. However, the effect of Al4Cu9 intermetallic compounds (IMCs) on shock Hugoniot of Al-Cu composites is far from clear, while the shock Hugoniot of Al-Cu composites mostly calculated by the Interpolation Model. In this letter, multiscale analysis of shock Hugoniot of Al-Cu composites using prediction models, muliti-stage light gas gun, and first-principles (FP) simulations was employed to investigate the effect of Al4Cu9 IMCs on the shock Hugoniot. Al-Cu composites with three different contents of Al4Cu9 IMCs were prepared by tape casting and powder metallurgic. The Isothermal Averaging Model has superiority in predicting the shock Hugoniot of Al-Cu composites at macroscale. For multi-scale analysis, the FP-simulated and experimental shock Hugoniot of Al-Cu composites with different microstructures have been compared. The sound velocity C0 and Hugoniot coefficient lambda values of Al- Cu composites with a high content of Al4Cu9 IMCs are found to be 28.0% and 13.9% higher, respectively, in comparison to those with a low content of Al4Cu9 IMCs. At atom-scale, the pseudogap of Al4Cu9 under high-pressure means stronger covalent bonds and resistance to compression deformation by FP methods. The generation and high-pressure mechanical properties of Al4Cu9 IMCs introduce errors in the prediction model.