Ni-Fe-Al共晶合金凭借优异的综合力学性能和良好的铸造性能备受关注。然而，双相共晶组织中特征微观结构的形成与演化机制以及其对宏/微观力学行为的影响尚不明确。本工作以Ni-Fe-Al共晶合金为研究对象，采用80%压下量冷轧结合650 ℃、3 min短时退火的热机械处理工艺，构造了由未再结晶fcc相(含高密度L1₂纳米相及位错网)与完全再结晶B2相(含高密度纳米畴及DO₃析出相)组成的片层状共晶组织，对合金在拉伸变形过程中的微结构演化和力学行为进行了系统研究。结果表明，该合金展现出了优异的强韧性匹配，其屈服强度和抗拉强度分别达到1286和1657 MPa，均匀伸长率为16.3%。合金的加工硬化率曲线呈现出典型“驼峰状”特征，当真应变从0.05增至0.10时，加工硬化率由3350 MPa显著提升至4480 MPa。合金的高屈服强度主要源于固溶强化、fcc相中位错网与L1₂纳米相的复合强化，以及B₂相中DO₃相对位错运动的阻碍作用。良好的韧性和加工硬化率的跃升，则归因于应力诱发的B2向fcc相转变以及两相协同变形机制。

Eutectic alloys with lamellar architectures have shown great potential in achieving an excellent combination of strength and ductility, yet it remains challenging to simultaneously optimize the constituent phases via conventional thermomechanical processing. This study investigates a Ni-Fe-Al eutectic alloy. A lamellar eutectic structure consisting of non-recrystallized FCC phase and fully recrystallized B2 phase was produced by cold rolling with an 80% thickness reduction followed by short-time annealing at 650 °C for 3 min. The FCC phase contains dense L12 nanoprecipitates and dislocation networks, while the recrystallized B2 phase consists of dense nanodomains and DO3 precipitates. The formation and evolution of the constructed microstructure and its influence on macro-mechanical behavior are systematically studied. The results show that the alloy achieves excellent mechanical properties with yield strength of 1286 MPa, tensile strength of 1657 MPa and uniform elongation of 16.3%. Notably, the work hardening rate curve exhibits a typical “hump-like” characteristic, increasing significantly from 3350 MPa at a true strain of 0.05 to 4480 MPa at a true strain of 0.1. The high yield strength is mainly attributed to the dislocation networks and L12 nanoprecipitates in the FCC phase, as well as the DO3 precipitates in the B2 phase, all of which impede dislocation motion. The good ductility and substantial enhancement of the work hardening rate benefit from the stress-induced B2 to FCC phase transformation driven by nanodomains and the cooperative deformation between the two phases during plastic deformation.