Hard secondary phases usually strengthen alloys at the expense of ductility. In this work, we made a dual-phase CrCoNi-O alloy containing a face centered cubic matrix and chromium oxide. On one side, the dispersed chromium oxide nano-particles impeded dislocation movement and increased the strength of the alloy. On another side, the spreading lattice distortion in CrCoNi-O high entropy solution locally relieved the severe interfacial mismatch and led to nanoscale variation of interfacial strain at the matrix-oxide interface, which facilitated dislocations’ transmission from one phase to another. Consequently, unlike the strong but brittle oxide nanoparticles used before, the oxide phase here can afford significant dislocation activities during material’s plastic deformation. Comparing the mechanical properties of CrCoNi-O alloys with and without chromium oxide particles, it was found that the yield strength of the dual-phase samples was twice of the single phase CrCoNi-O alloy and strong strain hardening was obtained with ultra-high deformation stability. High density of nanotwins formed in dual-phase samples under high stress, resulting in significant strain hardening according to the well-known twinning-induced plasticity (TWIP) effect. Our results shed light on optimizing the combination of strength and plasticity of compounds by modulating the variation of interfacial strain field based on the spreading lattice distortion.

坚硬的第二相通常以牺牲延展性为代价来强化合金。在这项工作中，我们制造了一种含有面心立方基体和氧化铬的双相 CrCoNi-O 合金。一方面，分散的氧化铬纳米颗粒阻碍了位错运动并提高了合金的强度。另一方面，CrCoNi-O高熵溶液中的扩展晶格畸变局部缓解了严重的界面失配，并导致基体-氧化物界面处界面应变的纳米级变化，从而促进了位错从一个相传递到另一个相。因此，与之前使用的强而脆的氧化物纳米颗粒不同，此处的氧化物相可以在材料的塑性变形过程中提供显着的位错活动。比较含有和不含氧化铬颗粒的 CrCoNi-O 合金的力学性能，发现双相试样的屈服强度是单相 CrCoNi-O 合金的两倍，并且在超高变形下获得了强应变硬化。稳定。在高应力下在双相样品中形成高密度的纳米孪晶，根据众所周知的孪晶诱导塑性 (TWIP) 效应导致显着的应变硬化。我们的结果揭示了通过基于扩展晶格畸变调节界面应变场的变化来优化化合物的强度和塑性的组合。结果表明，双相试样的屈服强度是单相CrCoNi-O合金的两倍，并获得了具有超高变形稳定性的强应变硬化。在高应力下在双相样品中形成高密度的纳米孪晶，根据众所周知的孪晶诱导塑性 (TWIP) 效应导致显着的应变硬化。我们的结果揭示了通过基于扩展晶格畸变调节界面应变场的变化来优化化合物的强度和塑性的组合。结果表明，双相试样的屈服强度是单相CrCoNi-O合金的两倍，并获得了具有超高变形稳定性的强应变硬化。在高应力下在双相样品中形成高密度的纳米孪晶，根据众所周知的孪晶诱导塑性 (TWIP) 效应导致显着的应变硬化。我们的结果揭示了通过基于扩展晶格畸变调节界面应变场的变化来优化化合物的强度和塑性的组合。