A gradient nanostructure was prepared in aged Inconel 718 by means of surface mechanical grinding treatment at room temperature. At the top surface layer with a thickness of ∼50 μm, the grain was refined down to extremely fine size (∼10 nm) and an abnormal Cr enrichment was detected on the grain boundaries. This Cr-segregated extremely-fine nanograin exhibits an unprecedented yield strength of ∼2935 MPa and superior GB stability against coarsening upon 800 °C annealing, providing a new sight on the preparation of superalloy with high performance.

中文翻译：

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使用 Cr 偏析纳米颗粒的 Inconel 718 合金实现 2.9 GPa 的屈服强度

通过室温下表面机械研磨处理，在老化的Inconel 718中制备了梯度纳米结构。在厚度约为 50 μm 的顶表层，晶粒细化至极细尺寸（~10 nm），并且在晶界上检测到异常的 Cr 富集。这种Cr偏析的极细纳米晶在800°C退火时表现出前所未有的屈服强度~2935 MPa和优异的晶界抗粗化稳定性，为高性能高温合金的制备提供了新的视角。