Search and Control of self-healing mechanism in fusion reactor materials

聚变反应堆材料自修复机制的探索与控制

基本信息

批准号：
09308015
负责人：
MATSUI Hideki
金额：
$ 22.4万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 2000
项目状态：
已结题

项目摘要

Self-healing property under particle irradiation is not uncommon to solid materials; many of the engineering materials keep their original shape even after several tens dpa, and this is exactly the result of self-healing property of the material. In this research, this intrinsic property, as well as extrinsic self-healing property given to these materials by adding precipitates, etc. is studied.Firstly, vanadium alloys that have been known to exhibit swelling decrease after going over a peak swelling at some intermediate dpa value. Precipitates in these materials have been examined closely, identifying their nature by utilizing selected area diffraction taken with imaging plates, EDS and PEELS. It became clear that interface between these precipitates and the matrix act as trapping sites, where interface-catalyzed recombination occurs, and play an important role in suppressing swelling. However, this phenomenon only cannot explain the observed decrease in swelling while dpa increases m … More onotonically. Increase in the precipitate density with dpa, caused by irradiation induced precipitation appears to be the mechanism explaining the decrease in swelling. Thus, it seems very important to give these precipitates good stability even after prolonged irradiation to high doses.One of the good example of self-healing property demonstrated under high dpa irradiation is the one observed in V-5Ti alloy. In this experiment, the specimen was first irradiated up to 17dpa in FFTF/MOTA. The specimen was further irradiated in JMTR up to 0.1dpa, which is much smaller to the irradiation in FFTF. The microstructure after 17dpa in FFTF/MOTA was indistinguishable to those in the specimen irradiated to 0.1dpa in JMTR. The microstructure basically consisted of tiny TiO2 precipitates. This means that this microstructure had been saturated below 0.1dpa and did not evolve even during the prolonged irradiation up to 17dpa. This observation is the result of remarkable self-healing mechanism due to the microstructure consisting of fine precipitates; the interface between the matrix and the precipitates act as catalysis for mutual recombination between self-interstitial atoms and vacancies.Computer code based on chemical rate theory has been developed in order to analyze the self-healing property observed experimentally. The input parameters have been obtained by using HVEM in situ irradiation technique. The result of the simulation was in good qualitative agreement while quantitative agreement was fair. The reason for this insufficient agreement between the theory and the experiment may partly be because of the insufficient approximation adopted in the theory. It is believed other mechanism is responsible for this and will be the topic of further research. Less

粒子照射下的自我修复特性并不罕见。即使经过几十亿TPA，许多工程材料仍保持原始形状，这正是材料自我修复属性的结果。在这项研究中，这种内在特性以及通过添加沉淀物等通过添加沉淀等通过的外部自我修复性能。首先，已知在以某些中间DPA值的峰转换后，已知已知会暴露出肿胀降低的钒合金。这些材料中的沉淀物已仔细检查，通过利用选定的成像板，ED和果皮采取的选定区域衍射来识别其性质。很明显，这些沉淀物与矩阵之间的界面作为捕获部位，在界面催化的重组发生，并在抑制肿胀中起重要作用。但是，这种现象不能解释观察到的肿胀减少，而DPA则增加了M…更典型地。由辐射引起的降水引起的DPA的珍贵密度增加似乎是解释肿胀减少的机制。这一点，即使长期辐照到高剂量之后，也要给这些宝贵的事物良好的稳定性。在高DPA辐照下证明的自我修复特性的一个很好的例子之一是在V-5TI合金中观察到。在此实验中，首先在FFTF/MOTA中将样品辐射为17dPa。在JMTR至0.1DPA中进一步辐照样品，这对于FFTF的照射要小得多。 17DPA在FFTF/MOTA中的微观结构与JMTR中辐照到0.1DPA的样品中的样品中没有区别。微结构基本上由微小的TiO2沉淀组成。这意味着该微观结构已饱和低于0.1dPa，即使在延长的辐照期间，也没有演变为17dPa。该观察结果是由于微观结构由精确精确组成的显着自我修复机制的结果。为了分析实验观察到的自我修复特性，已经开发了基于化学速率理论的自相关原子与空置代码之间相互重组的催化剂之间的催化剂。输入参数是通过使用HVEM原位辐照技术获得的。模拟的结果是良好的定性协议，而定量协议是公平的。理论与实验之间这种不足一致的原因可能部分是因为理论中采用的近似不足。人们认为其他机制是为此造成的，这将是进一步研究的主题。较少的