Understanding Dynamic Recrystallization-to-plasticity Linkages in Cold Spray via Nanomechanical Property Mapping and Profilometry-Based Indentation Plastometry

The high-strain rate impact phenomena underpinning solid-state metallurgical cold gas dynamic spray processing introduces severe plastic deformation states, which results in the formation of heterogeneous strain gradients throughout the consolidated microstructure. In addition, particle-particle interfacial dynamic recrystallization has been observed in various cold sprayed material systems. However, the degree of dynamic recrystallization achieved as a function of the impact velocity and the applied stress upon particle impact has yet to be linked to the plasticity of resultant consolidations. In turn, the present work utilizes various gas-atomized Al alloy feedstock powders, coupled with a range of particle impact velocities tuned through changes in carrier gas pressure and temperature to generate an array of fully dense consolidations with various degrees of interfacial dynamic recrystallization achieved. Consolidations will be studied through profilometry-based indentation plastometry testing and analysis and nanomechanical property mapping and clustering analysis methods. Consequently, a clear linkage between recrystallization and resultant uniform plastic stress-strain behavior will emerge through coupling mechanical property evaluation with dynamic recrystallization during cold spray processing.