Establishing the correlation between damage recovery and temperature in nuclear materials is vital to understanding material property degradation. Among the handful of topics related, one long-standing concern is the differences in damage recovery caused by different initial defect concentrations, with respect to ranges below and beyond the damage saturation limit. In this study, the temperature dependence of damage recovery has been comprehensively elucidated for pure tungsten, irradiated with 6 MeV copper ions at room temperature (RT), up to 0.05 dpa (non-saturated damage, n-SD) and 0.6 dpa (saturated damage, SD), and followed by isochronal annealing. Coupled transmission electron microscopy and Doppler broadening positron annihilation spectroscopy characterizations provided a full-probe-range picture of defect evolution. The varied initial defect concentrations caused retaining differences in damage recovery, but no substantial influence on temperature-dependent defect evolution. Moderate and dramatic damage recovery were identified below 973 K and above 1123 K in n-SD and SD tungsten, respectively. Most strikingly, nano-sized voids were confirmed at 473 K in both samples. Annealing at 1873 K saw the complete removal of defects in n-SD tungsten, but survival of a few dislocations via void pinning in SD tungsten. Full damage recovery in SD tungsten was projected to be ∼2000 K. The current revisit of damage recovery stages demonstrated the significance of encompassing scenarios of non-saturated and saturated defect concentrations. Accordingly, four damage recovery stages were redefined for heavy-ion irradiated tungsten, namely stage I (20 K–RT), stage II (RT–653 K), stage III (653–1123 K), and stage IV (1123–2000 K).

中文翻译：

---

重新审视损伤恢复阶段：重离子辐照钨中非饱和和饱和位移损伤的热演化


建立核材料损伤恢复与温度之间的相关性对于理解材料性能退化至关重要。在少数相关主题中，一个长期存在的问题是不同初始缺陷浓度在低于和超过损伤饱和极限的范围内引起的损伤恢复差异。在这项研究中，全面阐明了纯钨的损伤恢复的温度依赖性，在室温 (RT) 下用 6 MeV 铜离子辐照，高达 0.05 dpa（非饱和损伤，n-SD）和 0.6 dpa（饱和损伤）损伤，SD），然后进行等时退火。耦合透射电子显微镜和多普勒展宽正电子湮没光谱表征提供了缺陷演化的全探头范围图像。不同的初始缺陷浓度导致了损伤恢复的差异，但对温度相关的缺陷演化没有实质性影响。 n-SD 和 SD 钨分别在低于 973 K 和高于 1123 K 时发现中度和显着的损伤恢复。最引人注目的是，两个样品在 473 K 时都证实存在纳米尺寸的空隙。 1873 K 的退火完全消除了 n-SD 钨中的缺陷，但 SD 钨中通过空钉扎保留了一些位错。 SD 钨的完全损伤恢复预计为 ∼2000 K。当前对损伤恢复阶段的重新审视证明了涵盖非饱和和饱和缺陷浓度场景的重要性。据此，重离子辐照钨重新定义了四个损伤恢复阶段，即第一阶段（20 K-RT）、第二阶段（RT-653 K）、第三阶段（653-1123 K）和第四阶段（1123-2000）。 K）。