The deformation mechanism of nanocrystalline nickel under high strain rate

Understanding the deformation mechanisms of nanocrystalline is of great significance for its engineering applications. However, only a few studies focused on the deformation behavior of nanocrystalline at high strain rate. In this work, a high speed gas gun was applied to achieve high strain rate (~10⁶s⁻¹) deformation in nanocrystalline Ni with an average grain size of 35 nm. The deformed microstructure suggested that obvious stress-induced grain growth occurred. Nano-twinning and dislocation slipping were widely observed in the deformed structure. The underlying reasons for the prevalence of these two deformation mechanisms were also discussed.