Gradient structured metals have shown unique mechanical properties, such as high strength and good ductility. In this study, a gradient TWIP steel was fabricated by surface mechanical grinding treatment. The subsequent gradient structures consist of an outermost nanolaminate layer, a layer of deformation twins mixed with shear bands, and a deformation twinned layer. Tensile studies reveal that the introduction of gradient structures increases the yield strength significantly. Deformation induced hardening reaches maxima at the interface regions between the layers, presumably due to the distinct transition of high angle grain boundaries and twin boundaries near the interfaces and the accumulation of geometrically necessary dislocations under tension. These in-depth studies provide insight into the design of high-strength, strain hardenable metallic materials with gradient structures.

梯度结构金属已显示出独特的机械性能，例如高强度和良好的延展性。在这项研究中，通过表面机械研磨处理制造了梯度TWIP钢。后续的梯度结构由最外层的纳米层压层，混合有剪切带的变形孪晶层和变形孪晶层组成。拉伸研究表明，引入梯度结构可显着提高屈服强度。变形引起的硬化在层之间的界面区域达到最大值，大概是由于高角度晶界和界面附近的孪晶界的明显过渡以及在张力下几何必要位错的积累。这些深入的研究提供了对高强度设计的见解，