ABSTRACT The size, density, and distribution of helium (He) bubbles in a Ti-Ta single-phase alloy and a Ti/Ta dual-phase nanocomposite have been investigated using transmission electron microscopy. The Ti/Ta nanocomposite was fabricated via phase separation during high-temperature annealing of the single-phase Ti-Ta alloy. He ion implantation in the Ti-Ta single-phase alloy leads to the formation of nanoscale He bubbles (∼1.7 nm in size, ∼2.6 × 105/μm3 in volumetric density). He bubbles were found to segregate to grain boundaries. Under identical implantation conditions, numerous He bubbles also formed in the Ti/Ta nanocomposite. Closer inspection revealed that the He bubbles in the Ti-rich phase are smaller and of higher volumetric density (∼1.2 nm, ∼8.4 × 105/μm3) than those in the Ta-rich phase (∼3 nm, ∼1.8 × 105/μm3) and the single-phase alloy. He bubbles were also observed to decorate phase boundaries but they were generally smaller than those on grain boundaries. These results suggest that Ti/Ta phase boundaries are less conducive to the growth of large He bubbles than grain boundaries in the Ti-Ta single-phase alloy.

中文翻译：

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Ti-Ta合金和Ti/Ta纳米复合材料中氦气泡的对比研究

摘要已使用透射电子显微镜研究了 Ti-Ta 单相合金和 Ti/Ta 双相纳米复合材料中氦 (He) 气泡的大小、密度和分布。Ti/Ta纳米复合材料是在单相Ti-Ta合金高温退火过程中通过相分离制备的。在 Ti-Ta 单相合金中注入 He 离子导致形成纳米级 He 气泡（尺寸约为 1.7 nm，体积密度约为 2.6 × 105/μm3）。发现气泡分离到晶界。在相同的注入条件下，Ti/Ta 纳米复合材料中也形成了大量的 He 气泡。仔细观察发现，富钛相中的氦气泡比富钽相（~3 nm，~1.8 × 105/μm3）中的气泡更小，体积密度更高（~1.2 nm，~8.4 × 105/μm3）。 μm3) 和单相合金。还观察到气泡装饰相界，但它们通常比晶界上的小。这些结果表明，与 Ti-Ta 单相合金中的晶界相比，Ti/Ta 相界更不利于大 He 气泡的生长。