In situ study of self-ion irradiation damage in W and W–5Re at 500 °C
In situ study of self-ion irradiation damage in W and W–5Re at 500 °C
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DOI：
10.1080/14786435.2012.754110
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发表时间：
2013-05
影响因子：
1.6
通讯作者：
X. Yi;M. Jenkins;M. Briceno;S. Roberts;Zhongfu Zhou;M. Kirk
中科院分区：
文献类型：
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作者：
X. Yi;M. Jenkins;M. Briceno;S. Roberts;Zhongfu Zhou;M. Kirk
在500 °C下，对W和W-5 Re进行了原位自离子辐照（150 keV W+），剂量范围为1016至1018 W+m−2（101.0 dpa）。在两种材料中均观察到早期损伤形成（1016 W +m−2）。使用TEMACI软件的黑白对比实验和图像模拟表明，在单个级联中形成了空位环，因此，环成核机制可能是“级联扩散”。动态观察表明，在较高的剂量下，间隙环的成核和生长，弹性环的相互作用可能涉及环伯格斯矢量的变化。弹性相互作用还可以促进环反应，例如吸收或聚结或环串形成。W和W-5 Re中的环在500 °C退火后保持稳定。环的一维跳跃（B = 1/2）仅见于W.在最终剂量（1018 W +m−2）下，W-5 Re中观察到略微密集的损伤微观结构。这两种材料都有大约3-4 × 1015圈m−2。详细的辐照后分析进行了循环的大小为14 nm。B = 1/2 × 111 × 111（× 75%）和B = × 100 × 100（× 25%）环均存在。在安全方向下进行内外对比实验以确定环的性质。在W中，1/2 <$111 <$N环的空位-空位环比接近1，在W-5 Re中，1/2 <$111 <$N环和1/2 <$100 <$N环的空位-空位环比接近1。而W. Re似乎限制环的流动性，导致较小的平均环的大小和较高的数密度的W-Re合金。
In situ self-ion irradiations (150 keV W+) have been carried out on W and W–5Re at 500 °C, with doses ranging from 1016 to 1018 W+m−2 (∼1.0 dpa). Early damage formation (1016W+m−2) was observed in both materials. Black–white contrast experiments and image simulations using the TEMACI software suggested that vacancy loops were formed within individual cascades, and thus, the loop nucleation mechanism is likely to be ‘cascade collapse’. Dynamic observations showed the nucleation and growth of interstitial loops at higher doses, and that elastic loop interactions may involve changes in loop Burgers vector. Elastic interactions may also promote loop reactions such as absorption or coalescence or loop string formation. Loops in both W and W–5Re remained stable after annealing at 500 °C. One-dimensional hopping of loops (b = 1/2 ⟨111>) was only seen in W. At the final dose (1018W+m−2), a slightly denser damage microstructure was seen in W–5Re. Both materials had about 3–4 × 1015 loops m−2. Detailed post-irradiation analyses were carried out for loops of size ⩾ 4 nm. Both b = 1/2 ⟨111⟩ (∼75%) and b = ⟨100> (∼25%) loops were present. Inside–outside contrast experiments were performed under safe orientations to determine the nature of loops. The interstitial-to-vacancy loop ratio turned out close to unity for 1/2 ⟨111⟩ loops in W, and for both 1/2 ⟨111⟩ and ⟨100⟩ loops in W–5Re. However, interstitial loops were dominant for ⟨100⟩ loops in W. Re seemed to restrict loop mobility, leading to a smaller average loop size and a higher number density in the W-Re alloy.