V-4Cr-4Ti was irradiated by He and subsequent V/self-ions at 773 K to simulate the effect of the damages generated under near-service conditions on irradiation hardening. Microstructure observation and hardness test were carried out by transmission electron microscopy (TEM) and nanoindentation testing. Microstructure analysis showed that bubbles, dislocation loops and precipitates were produced whether samples were irradiated by He or He/V. Edge dislocation was observed by high-resolution images. The nanoindentation results showed that hardening appeared after irradiation, and hardness increment after He irradiation is 4.41 GPa, 6.2 GPa for He/V. Meanwhile, based on damage characterization, the irradiation hardening was also analyzed using the dispersion barrier hardening model (DBH), which showed that the main cause of hardening was dislocation loops. In addition, the deviation was discussed between the hardness increment obtained by nanoindentation testing and that calculated based on DBH.

中文翻译：

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V-4Cr-4Ti 近服役条件下 He+ 辐照硬化和随后的 V/自离子辐照研究

V-4Cr-4Ti 在 773 K 下被 He 和随后的 V/自离子辐照，以模拟在接近使用条件下产生的损伤对辐照硬化的影响。通过透射电子显微镜（TEM）和纳米压痕测试进行显微组织观察和硬度测试。微观结构分析表明，无论是He还是He/V辐照样品，都会产生气泡、位错环和析出物。通过高分辨率图像观察到边缘位错。纳米压痕结果表明，辐照后出现硬化，He辐照后硬度增量为4.41 GPa，He/V辐照后硬度增量为6.2 GPa。同时，在损伤表征的基础上，利用色散势垒硬化模型（DBH）对辐照硬化进行了分析，结果表明硬化的主要原因是位错环。此外，还讨论了纳米压痕测试得到的硬度增量与根据DBH计算得到的硬度增量之间的偏差。