Unraveling Spall Strength Dependencies Through Laser Driven Micro-plate Impact High-Throughput Experiments

Spallation is a dynamic failure process that occurs under high strain rates, where intense tensile hydrostatic loading leads to internal failure within materials. In ductile metals, this failure process follows the stages of void nucleation, growth, and coalescence, which is strongly influenced by the material's microstructure. In this study, an automated high-throughput Laser-driven Micro-flyer plate Impact (LMI) experimental system was utilized to investigate the dependence of spall strength on material microstructure including grain size and texture along with loading parameters such as shock stress and strain rate, using copper as a model material. Nanocrystalline copper specimens were prepared using a sputter coating methodology, and specimens were further annealed to grow grains sizes. The material fabrication and experimental procedure were automated to accelerate the exploration process. The high throughput methodology allows for data generation with associated uncertainties allowing for a stochastic evaluation of spall strength at extremely high strain rates (105 to 107) and shock pressures (4 to 11 GPa).