Unraveling Spall Strength Dependencies through Laser Driven Micro-flyer 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 and loading parameters including shock stress and strain rate using pure copper as a model material. Nanocrystalline copper speciments were prepared using a sputter coating methodology, and specimens were further annealed to grow grains sizes by two orders of magnitude. The material fabrication and experimental procedure were automated to accelerate the exploration process. The study utilizing the high throughput experimental data generation, provides stochastic dependence of spall strength on microstructure features and loading parameters.