Gradient structure (GS) possesses a typical trans-scale grain hierarchy with varying internal plastic stability, and the mutual plastic accommodation plays a crucial role in its superior strength-ductility combination. Using the in-situ synchrotron X-ray diffraction (XRD) during tensile loading, we measured lattice strains sequentially from the nanostructured (NS) surface layer to the central coarsegrained (CG) layer to elucidate when and how plastic accommodation occurs and evolves within the GS, along with their roles in plastic deformation and strain hardening. Throughout the tensile deformation, two types of plastic incompatibility occur in the GS. One is an extended elastoplastic transition due to layer-by-layer yielding. The other is strain localization and softening in the NS layer, in contrast with the stable plastic deformation in the CG layer. Plastic accommodation thus occurs concurrently and manifests as both an inter-layer and intra-layer change of stress state throughout tensile deformation. This produces different micromechanical responses between layers. Specifically, the NS layer initially experiences strain hardening followed by an elastoplastic deformation. The hetero-deformation induced hardening, along with forest hardening, facilitates a sustainable tensile strain in the NS layer, comparable to that in the CG layer.

梯度结构（GS）具有典型的跨尺度晶粒层次结构，具有不同的内部塑性稳定性，并且相互的塑性适应在其优异的强度-延展性组合中起着至关重要的作用。使用原位同步加速器X射线衍射（XRD）在拉伸载荷过程中，我们依次测量了从纳米结构（NS）表面层到中央粗颗粒（CG）层的晶格应变，以阐明塑性容纳的时间和方式以及在GS中如何演化以及如何演化。在塑性变形和应变硬化中的作用。在整个拉伸变形过程中，GS中发生两种类型的塑性不兼容。一种是由于逐层屈服导致的扩展的弹塑性转变。另一个是与CG层中稳定的塑性变形相比，NS层中的应变局部化和软化。因此，塑性调节同时发生，并且在整个拉伸变形中表现为应力状态的层间和层内变化。这会在层之间产生不同的微机械响应。具体来说，NS层最初经历应变硬化，然后发生弹塑性变形。与CG层相比，异质变形诱发的硬化以及森林的硬化促进了NS层中可持续的拉伸应变。