The Cu–Ni–Mn–Fe alloy is prepared to study its precipitation behavior and mechanical properties during aging under elevated compression stresses. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), hardness and tensile tests are used for this investigation. The results indicate that the stress-aging treatment leads to the formation of fine, equiaxed grains and twins within the matrix of Cu–Ni–Mn–Fe alloy. During the stress-aging, the density of θ-MnNi precipitates initially decreases and then increases. The stress is further increased from 220 to 385 MPa, the vacancy concentration and dislocation density increase rapidly owing to creep deformation, while the strain-induced effect accelerates the precipitation of θ-MnNi. The results show that the tensile strength and hardness of Cu–Ni–Mn–Fe alloy initially decrease and then increase, and the tensile strength and hardness of the Cu–Ni–Mn–Fe alloy are 890 MPa and 274 HB under the compressive stress of 385 MPa, and the elongation remains at 8.72%. It is mainly attributed to the application of compression stresses during aging, which can enhance both the strength and ductility of the alloy.

制备了Cu-Ni-Mn-Fe合金以研究其在高压应力作用下的时效过程中的沉淀行为和力学性能。本研究使用透射电子显微镜（TEM），扫描电子显微镜（SEM），X射线衍射（XRD），硬度和拉伸试验。结果表明，应力时效处理导致在Cu-Ni-Mn-Fe合金基体内形成细小的等轴晶粒和孪晶。在应力时效过程中，θ- MnNi析出物的密度先降低然后增加。应力从220 MPa进一步增加到385 MPa，由于蠕变变形，空位浓度和位错密度迅速增加，而应变诱导效应加速了θ的析出-MnNi。结果表明，Cu–Ni–Mn–Fe合金的拉伸强度和硬度先降低后增加，在压缩应力下，Cu–Ni–Mn–Fe合金的拉伸强度和硬度分别为890 MPa和274 HB。 385MPa，伸长率保持在8.72％。这主要归因于时效过程中施加的压缩应力，可以同时提高合金的强度和延展性。