Experimental study on the obstacle strength factor to dislocation motion for the evaluation of radiation embrittlement of nuclear materials

位错运动障碍强度因子评价核材料辐射脆化的实验研究

基本信息

批准号：
14208057
负责人：
MATSUI Hideki
金额：
$ 34.61万
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：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

For the evaluation of lifetime of nuclear materials, it is important to examine the interaction of dislocations and obstacles. A number of researches have been devoted for this objective by observing obstacles by TEM, and from their size and number density, the induced hardening due to these obstacles was evaluated. Here, the important parameter is the obstacle strength factor that usually denoted as α, and was derived theoretically so far. However, the accuracy was usually not sufficient, and it was a customary in many cases that this parameter was treated as an adjustable parameter. The detection of obstacles, on the other hand, is very difficult in some cases, e.g. Cu-rich precipitates in RPVS with conventional TEM. Three-D Atom Probe can detect such tiny precipitates, but because of the limited size of sampling volume, it is difficult to obtain statistically significant value of the density and average size. In the present study, these tiny precipitates were detected as cusps on di … More slocation lines interacting with the precipitates. This is one of the major accomplishments of the technique developed here. Moreover, the obstacle strength parameter α can be measured directly from the apex angle of the cusp. Striking agreement was obtained between the hardening obtained from macroscopic mechanical test with that obtained from in situ TEM. This result shows the validity of the technique. MD simulation of the interaction process between dislocations and obstacles was carried out. The results were used to understand the microscopic process that cannot be examined by in situ TEM study. MD study further verified the method developed in this study.Ultrasonic attenuation measurements under external stress and amplitude dependent internal friction measurements were also carried out. The former technique was developed in order to evaluate non-destructively radiation hardening. In situ TEM study, ultrasonic attenuation, and internal friction are all combined to yield a comprehensive view on the interaction of dislocations and obstacles. In the present study, it was demonstrated that ultrasonic attenuation measurement under external stress is a very promising method for non-destructive evaluation of radiation hardening. Less

为了评估核材料的寿命，重要的是要检查位错和障碍的相互作用。通过观察TEM的障碍，从其大小和数量密度观察障碍物，对这一目标进行了许多研究，从而评估了由于这些障碍而引起的硬化。在这里，重要参数是通常表示为α的障碍强度因子，迄今为止是理论上得出的。但是，准确性通常不够，在许多情况下，该参数被视为可调参数。另一方面，在某些情况下，很难发现障碍物，例如带有常规TEM的RPV中富含Cu的沉淀。三-D原子探针可以检测到这种微小的沉淀物，但是由于采样量的大小有限，因此很难获得密度和平均大小的统计学意义。在本研究中，这些微小的沉淀物被视为DI上的尖头……更多与沉淀物相互作用的位置线。这是这里开发的技术的主要成就之一。此外，可以直接从尖端的顶角度测量障碍强度参数α。从宏观机械测试获得的硬化与从原位TEM获得的硬化获得了惊人的一致性。该结果显示了该技术的有效性。对位错和障碍之间的相互作用过程进行了MD模拟。结果用于了解无法通过原位TEM研究来检查的显微镜过程。 MD研究进一步验证了本研究中开发的方法。还进行了外部应力和放大器依赖性内部摩擦测量的超声衰减测量。为了评估非破坏性辐射硬化，开发了前一种技术。原位研究，超声波衰减和内部摩擦都合并在一起，以对位错和障碍的相互作用产生全面的看法。在本研究中，证明在外部压力下的超声衰减测量是一种非常有前途的方法，可用于对放射硬化的无损评估。较少的