反应堆中嬗变产物氦泡在镍基合金晶界上生长机制研究

项目名称： 反应堆中嬗变产物氦泡在镍基合金晶界上生长机制研究

项目编号： No.11505266

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 王呈斌

作者单位： 中国科学院上海应用物理研究所

项目金额： 22万元

中文摘要： 镍基合金具有较好的抗腐蚀和抗高温蠕变性能，因此镍基合金被认为是第四代核反应堆的候选材料之一。中子与镍发生嬗变反应生成氦，并在合金中聚集导致氦脆效应，从而影响反应堆的安全。纳米核材料中大量的晶界构建了大量氦的“成核场所”，从而有可能抑制氦脆的产生，其晶界在控制氦脆中的作用是国际上的研究热点和难点。晶界中的位错类型和晶界能在氦泡的的形成和生长过程中起着重要的作用，然而，最近实验结果表明不同的金属类型起作用的位错类型不同，而且，晶界能明显不是影响氦泡尺寸的唯一因素。另外，晶界上氦泡的状态方程是决定氦泡长大过程的关键因素，但能够精确的描述氦和金属原子相互作用的状态方程仍然缺乏，与熔盐堆相关的镍基合金相关研究更是不足。本研究拟采用第一性原理和分子动力学模拟相结合的方法研究氦泡在镍基合金中位错、晶界上的形成和长大过程，理解晶界上“氦泡到空洞”转化的物理机制，力争为设计新的抗辐照纳米合金提供理论依据。

中文关键词： 氦脆；纳米核材料；晶界；抗辐照材料；辐照损伤

英文摘要： Nickel-based alloys have good corrosion resistance and high temperature creep performance, nickel-based alloy is considered to be one of the candidates for the fourth generation of nuclear reactors. Neutron transmutation reaction introduces helium and leads to helium embrittlement effect, thus affecting the safety of the reactor. nuclear nano-material has a large number of grain boundaries which are considered as helium nucleation sites, making it possible to suppress the helium embrittlement, its role in the control of helium embrittlement is a hot and difficult topic. Dislocations at grain boundaries and grain boundaries type can play an important role in the formation and growth of bubbles of helium, however, recent experimental results indicate that the type of dislocations which play important roles in gathering helium in metals are different and the grain boundary energy are not the only significant factor affecting helium bubble size. In addition, the equation of state for helium bubbles at grain boundary is the key factors determining helium bubble growth, but the state of equation described with the interaction between helium and metal atoms is still lacking, nickel-based alloys and molten salt reactor research related to is specially insufficient. This investigation intends to study helium bubbles growth process at grain boundaries in nickel-based alloys in order to understand the bubble to void transformation mechanisms, and strive to provide a theoretical basis for the design of new anti-radiation alloys.

英文关键词： Helium embrittlement;Nano-nuclear materials;Grain boundary;Radiation resistance material;Irradiation damage