Despite having excellent mechanical properties, the applications of many Ni-based alloys are limited owing to their modest yield strengths. Grain refinement has provided the opportunity for further strengthening, while also requiring significant and undesirable compromises in ductility. In this work, a novel Ni-based alloy with a heterogeneous, partially recrystallized structure was designed by controlling the thermomechanical process after cold-rolling. The alloy exhibits a superior combination of ~ 2 GPa yield strength and ~ 9% tensile uniform elongation, surpassing the room-temperature mechanical performance of most Ni-based alloys reported in recent years. The ultrahigh strength originates from the synergistic strengthening effects of grain boundaries, high-density dislocations, and γ' nanoparticles. Meanwhile, the considerable ductility is primarily ascribed to the improved strain hardening ability and delayed necking induced by two mechanisms: (i) the formation of high-density stacking faults, Lomer-Cottrell locks, and deformation twins in the recrystallized grains; (ii) the abundant dislocations pile-up at the interface between the γ' nanoparticles and matrix. These findings suggest that the design of partially recrystallized structures has great potential to solve the strength-ductility trade-off in Ni-based alloys.

尽管具有优异的机械性能，但许多镍基合金的应用由于其适度的屈服强度而受到限制。晶粒细化提供了进一步强化的机会，同时也需要在延展性方面做出重大且不希望的妥协。在这项工作中，通过控制冷轧后的热机械过程，设计了一种具有异质、部分再结晶结构的新型镍基合金。该合金表现出约 2 GPa 屈服强度和约 9% 拉伸均匀伸长率的卓越组合，超过了近年来报道的大多数镍基合金的室温机械性能。超高强度源于晶界、高密度位错和γ'纳米粒子的协同强化效应。同时，相当大的延展性主要归因于应变硬化能力的提高和由两种机制引起的延迟颈缩：（i）再结晶晶粒中高密度堆垛层错、Lomer-Cottrell锁和变形孪晶的形成； (ii) γ '纳米粒子和基质之间的界面处大量位错堆积。这些发现表明，部分再结晶结构的设计对于解决镍基合金的强度-延展性权衡具有巨大的潜力。