Microstructural evolution of a nanotwinned steel under extremely high-strain-rate deformation

Microstructures and strengthening mechanism of 2D laminated structures in Ni balls after high‐speed collisions with 316 L stainless steel

“…Moreover, it is also very meaningful to understand the deformation mechanism of metallic materials at a high‐strain‐rate 6 . It is well known that the SPD at very high strain rates is a complex process, at the same time, it should be important to study dislocation configuration, nanotwin distribution and phase transformation during the SPD at high strain rates 7 . It was found that the SPD at high‐strain‐rate was potential to induce numerous defects and interfaces, which resulted in the inhomogeneous microstructure along with large strain gradients 8 .…”

“…6 It is well known that the SPD at very high strain rates is a complex process, at the same time, it should be important to study dislocation configuration, nanotwin distribution and phase transformation during the SPD at high strain rates. 7 It was found that the SPD at high-strain-rate was potential to induce numerous defects and interfaces, which resulted in the inhomogeneous microstructure along with large strain gradients. 8 Lu et al 9 suggested that an ultra-high strain rate was a solution for the grain refinement in the laser shock processing.…”

High Strain Rate Response of In-Situ TiB2/7055 Composite by Taylor Impact

“…Zhu et al [ 10 ] found that the dynamic deformation behavior of high-volume fraction (up to 60%) PRAMCs was affected by strain rate hardening and adiabatic heating softening mechanism, which eventually led to a mixture of brittle cracking of reinforcing phase and ductile fracture of matrix alloy in the composite. Zhou et al [ 25 ] studied the microstructure evolution of nano-twinned steel during ballistic impact by nano-indentation, scanning electron microscope (SEM), transmission electron microscope (TEM) and other techniques and they found that high strain rate promoted dislocation multiplication (the activation of dislocation source leading to the increase of dislocation density) and phonon drag effect of dislocation movement (induced by interactions between mobile dislocation and lattice vibration), remarkably increasing the hardness in the severe deformation zone. Obvious recrystallization occurred in the severe deformation zone due to temporarily to the significant temperature rise.…”