Zhenli Mi

Evading the strength- ductility trade-off dilemma in steel through gradient hierarchical nanotwins

The strength–ductility trade-off has been a long-standing dilemma in materials science. This has limited the potential of many structural materials, steels in particular. Here we report a way of enhancing the strength of twinning-induced plasticity steel at no ductility trade-off. After applying torsion to cylindrical twinning-induced plasticity steel samples to generate a gradient nanotwinned structure along the radial direction, we find that the yielding strength of the material can be doubled at no reduction in ductility. It is shown that this evasion of strength–ductility trade-off is due to the formation of a gradient hierarchical nanotwinned structure during pre-torsion and subsequent tensile deformation. A series of finite element simulations based on crystal plasticity are performed to understand why the gradient twin structure can cause strengthening and ductility retention, and how sequential torsion and tension lead to the observed hierarchical nanotwinned structure through activation of different twinning systems.

Texture evolution of commercial pure Ti during cold rolling and recrystallization annealing

X-ray diffraction (XRD) was employed to analyze the texture evolution of commercial pure (CP) Ti during cold rolling and recrystallization annealing. The texture components were measured by electron backscattered diffraction (EBSD) after recrystallization annealing. The CP Ti tends to form a texture with the basal pole tilted 30°–40° away from the normal direction toward the transverse direction. The texture of the initial hot-rolled plate can be classified into three kinds, i.e., the pyramid texture

Influence of Cold Rolling Reduction on Microstructure and Mechanical Properties of Twip Steel

\left( {\bar 1013} \right)\left[ {5\bar 2\bar 30} \right]

In-situ observation on the deformation behaviors of Fe-Mn-C TWIP steel

and

Deformation mechanism transition in Fe–17Mn–0.4C–0.06V TWIP steel with different strain rates

\left( {\bar 2021} \right)\left[ {10\bar 15} \right]

Hot deformation behaviour and processing map of a typical Fe-Mn-Si-Cr steel for automotive body structures

, the basal plane texture