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Study of dynamical behavior of point defect clusters in neutron-irradiated metals at elevated temperature by electron microscopy

电子显微镜研究高温中子辐照金属中点缺陷簇的动力学行为

基本信息

批准号：
10450233
负责人：
SHIMOMURA Yoshiharu
金额：
$ 1.41万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Following seven items were published during 3 years supports of GRAND-IN-AID FOR SCIENTIFIC RESEARCH (1) A computer simulation study on displacement damage formation near sigma-5 boundary in Silver. (2) Segregation of interstitial clusters near dislocations in FCC metals neutron-irradiated at high temperature. (3) Changes of the dislocation sink efficiency of point defect absorption for the fluence in neutron-irradiated FCC metals at high temperature. (4) Multiplication mechanism of dislocations in neutron-irradiated FCC metals at high temperature. (5) Atomistic mechanism of nucleation and growth of stacking fault tetrahedra (sft) and voids in neutron-irradiated FCC metals at high temperature. (6) Atomistic mechanism of damage structure evolution in fission neutron irradiated FCC metals at high temperature. (7) Atomistic mechanism of damage structure evolution in D-T fusion 14 MeV neutron irradiated FCC metals. In these works, the most significant result is the atomistic mechanism of the formation of vacancy clusters of voids and sft in neutron-irradiated FCC metals at high temperature. TEM observations showed that both of voids and sft form in an FCC metal simultaneously. The number of vacancy that is contained in a void is more than 500, while the number of vacancy in an sft is less than 250. Computer simulation shows that vacancy clusters can move as a cluster through Damask-Dienes-Weizer relaxation after the structure relaxes to string-like cluster. When a number of vacancies in a v-cluster are less than 250, the cluster relaxes to an sft. The sft is the most stable structure in Cu and Ni. When a number of vacancies in a cluster are more than 500, it does not relax to a one (111) platelet due to an anisotropy. A cluster relaxes to a spherical configuration, which are composed by a large number of {111} v-platelets. Its spherical clusters finally relax to a void.

（1）银中σ 5界面附近位移损伤形成的计算机模拟研究。(2)高温中子辐照面心立方金属中位错附近间隙原子团的偏聚。(3)中子辐照面心立方金属高温点缺陷吸收位错阱效率随注量的变化。(4)中子辐照面心立方金属高温位错增殖机制。(5)中子辐照面心立方金属中高温堆垛层错四面体和空洞形核与生长的原子机制。(6)裂变中子辐照面心立方金属高温损伤结构演化的原子机制。(7)D-T聚变14 MeV中子辐照FCC金属损伤结构演化的原子机制在这些工作中，最重要的结果是高温下中子辐照FCC金属中空隙和sft空位簇形成的原子机制。透射电镜观察表明，在面心立方金属中，空洞和sft同时形成。包含在空隙中的空位的数量大于500，而SFT中的空位的数量小于250。计算机模拟表明，空位团簇在结构弛豫成弦状团簇后，可以通过Damask-Dienes-Weizer弛豫作为团簇运动。当v-簇中的空位数小于250时，簇松弛到sft。sft是Cu和Ni中最稳定的结构。当团簇中的空位数大于500时，由于各向异性，它不会弛豫为一个（111）片晶。团簇弛豫为球形构型，由大量{111} v-片晶组成。它的球状星团最终松弛成一个空洞。