Tape Casting Preparation and Quasi-Isentropic Loading Properties of Al-Cu Periodic Laminated Gradient Materials

Periodic laminated gradient materials with independently controllable wave impedance distributions and minimal physical phase reactions are now being used for quasi-isentropic loading. However, the wave system action time of the currently periodic laminated gradient materials are on the order of nanoseconds due to limitations in preparation technology, which makes it difficult to achieve loading times of significantly larger magnitudes. In this study, the tape casting process was systematically investigated, and large-size Al-Cu periodic laminated gradient materials were successfully prepared using a combined technique of tape casting and low-temperature densification. The quality and quasi-isentropic loading properties were verified through microstructural characterization and dynamic loading experiments. The results show that the gradient structure of the material is well-defined, the interlayer parallelism is high, the layer interface is well bonded, and that no crack defects or intermetallic compounds generated. The material exhibits a densification of 95.8% and a total deformation less than 15 μm. When the Al-Cu periodic laminated gradient material was loaded with a 6 μm-thick Al target at a driving speed of 510.6 m/s, the loading waveform oscillated and increased with a loading time approaching 1 μs. The loading trends of simulation results agree well with the experimental curves through correcting Al/Cu periodic layer thickness and Cu layer wave impedance. The materials demonstrate excellent quasi-isentropic loading characteristics. This study provides theoretical basis, technical support and new preparation techniques for the application of periodic laminated gradient materials.