The heavy-ion irradiation behavior of bulk zirconium-niobium multilayered composites was investigated up to large doses. Multilayers with an average individual layer thicknesses ranging between 15 and 80 nm were synthesized by accumulative roll bonding technique. The irradiation was performed with a defocused 7 MeV Zr²⁺ ion beam at 500 °C. The maximum dose achieved was ∼145 dpa at the depth of ∼1.5 μm from the irradiated surface. Sub-surface microstructural damage and the chemical redistribution were characterized by transmission electron microscopy and energy dispersive spectroscopy, respectively. Irrespective of the layer thicknesses, the irradiation condition caused layer instability and the extent of damage varied with the dose levels. Doses lesser than ∼60 dpa caused layer fragmentation and greater than ∼60 dpa resulted in layer dissolution. The chemical mixing of layers occur to a depth of ∼1 μm, consuming multiple bi-layer periods. Despite the elevated irradiation temperature (500 °C) and a slightly positive heat of mixing (+6 kJ/mol), no phase separation was observed and single-phase was retained in the mixed region. The results demonstrate that chemical mixing was facilitated by the liquid phase miscibility of Zr and Nb, which propelled the interdiffusion within the thermal spikes towards mixing.

研究了大剂量锆铌多层复合材料的重离子辐照行为。多层的平均单层厚度范围在 15 和 80 nm 之间是通过累积滚压技术合成的。用散焦的 7 MeV Zr ²⁺进行辐照离子束在 500 °C。在距辐照表面约 1.5 微米的深度处达到的最大剂量为约 145 dpa。亚表面微观结构损伤和化学重新分布分别通过透射电子显微镜和能量色散光谱进行表征。无论层厚如何，辐照条件都会导致层不稳定，并且损伤程度随剂量水平而变化。小于~60 dpa 的剂量会导致层破碎，而大于~60 dpa 的剂量会导致层溶解。层的化学混合发生在~1μm 的深度，消耗多个双层周期。尽管辐照温度升高 (500 °C) 和混合热略为正 (+6 kJ/mol)，但未观察到相分离，混合区域中仍保留单相。