We investigate nano-scale irradiation-induced precipitation in a ZrSnFeCrNi-alloy (Zircaloy-2) by combining atom probe tomography (APT) for chemical detail with scanning transmission electron microscopy (STEM) and high resolution energy dispersive X-ray (EDX) spectroscopy for wider context and complimentary and correlative TEM diffraction techniques for crystallographic relationships. We find that Fe and Cr-rich nano-rods precipitate in Zircaloy-2 following proton irradiation at 350 °C to a low dose of ∼2 dpa. The long-axis of the nano-rods are aligned in a direction 12–15° from the Zr matrix $〈0001〉$, align in the basal plane and are of width 1.5–5 nm. Smaller rods are of APT-determined composition Zr₄(Fe_0.67Cr_0.33), tending towards Zr₃(Fe_0.69Cr_0.31) as the rod volume increases to > ∼400 nm³, in agreement with STEM-EDX determination of composition resembling that of Zr₃Fe with Cr replacing some of the Fe. The Fe/Cr ratio has been shown to increase with distance from the nearest partially-dissolved Zr(Fe,Cr)₂ phase particle. The nucleation of nano rods has implications for macroscopic irradiation-induced deformation phenomena, irradiation-induced hardening and the evolution of dislocation loops and other defects.

我们通过结合原子探针层析成像（APT）的化学细节，扫描透射电子显微镜（STEM）和高分辨率能量色散X射线研究Zr Sn Fe Cr镍合金（Zircaloy-2）中纳米级辐照诱发的沉淀（EDX）光谱技术可提供更广泛的应用环境，以及互补和相关的TEM衍射技术可实现晶体学关系。我们发现，在350°C的质子辐照至约2 dpa的低剂量后，富铁和富铬的纳米棒在Zircaloy-2中沉淀。纳米棒的长轴在与Zr矩阵成12–15°的方向上对齐$〈0001〉$，在基面上对齐，宽度为1.5-5 nm。较小的棒具有APT决定的成分Zr ₄（Fe _0.67 Cr _0.33），随着棒体积增加到>〜400 nm ³，趋向Zr ₃（Fe _0.69 Cr _0.31），这与STEM-EDX确定类似， Zr ₃ Fe中的Cr代替了部分Fe。已经表明，Fe / Cr比随距最近的部分溶解的Zr（Fe，Cr）_2的距离而增加相粒子。纳米棒的成核作用对宏观的辐照引起的变形现象，辐照引起的硬化以及位错环的演变和其他缺陷具有影响。