Investigation of Solid State Reaction by Means of Direct Observation of Atomistic Structural Changes

直接观察缺陷反应最优越的方法是在高压电子显微镜下利用高能电子照射；(a)系统地研究了溶质添加对缺陷结构演变的影响；(b)建立了一种通过叠加电子辐照识别中子辐照材料中小点缺陷团簇性质的方法，并应用于代表性材料；(c)阐明了位错周围应变场对级联缺陷的影响。(d)成功检测了电子辐照诱导位错环生长过程中点缺陷反应过程的随机波动；(e)采用新设计的间歇辐照技术测量了短弛豫现象。对于高能中子辐照诱导的缺陷组织：(g)研究了级联碰撞诱导的缺陷点的归宿与微观结构演变的关系；(h)系统地研究了溶质元素对缺陷微观结构演变的影响；(i)研究了中子辐照过程中缺陷反应随温度变化的机理。结晶金属无位错塑性变形是本课题研究的重点和新课题。(k)通过对点缺陷团簇出现和消失的动态观察，得出点缺陷是作为分散的点缺陷引入的，而不是作为点缺陷团簇引入的结论；(l)通过塑性变形析出物的变形成功地测量了局部应变；(m)采用含有各种次生缺陷的试样进行了变形模式的研究；(n)所有这些实验结果都导致了在极高内应力条件下用滑动单元代替位错的变形新机制的提出。在高速变形实验中，应变速率达到10^7/s，在应变速率超过10^5/s的情况下，缺陷结构发生了显著变化。少

The most superior method of direct observation of defect reactions is to utilize high energy electron irradiation in a high-voltage electron microscope : (a) A systematic investigation has been performed on the effect of solute addition to defect structure evolution, (b) A method of the identification of the nature of small point defect clusters in neutron irradiated materials was established by superimposing electron irradiation and applied to representative materials, (c) Effect of strain field around dislocation on cascade defects was elucidated, (d) Detection of stochastic fluctuation of point defect reaction processes was successfully made during the growth of electron irradiation-induced dislocation loops, (e) Measurement of short relaxation phenomena was made by newly designed intermittent irradiation technique. As for the defect microstructures induced by high energy neutron irradiation : (f) The role of electron microscopically invisible small defect clusters in iron was eluci … More dated, (g) Relation between the destination of cascade collision induced point defects and the microstructure evolution was studied, (h) Effect of solute elements to the defect microstructure evolution was systematically investigated, (i) The mechanism of defect reaction during neutron irradiation with temperature variation was also studied. Plastic deformation of crystalline metals without dislocation was the most important and new subject in this research project : (j) Absence of the operation of dislocations was confirmed by direct observation of the progress of deformation in an electron microscope, (k) From the dynamic observation of the appearance and disappearance of point defect clusters, point defects are concluded to be introduced as dispersed point defects, but not as point defect clusters, (l) Local strain was successfully measured by the deformation of plastically deformable precipitates, (m) Deformation mode was examined by using samples containing various kinds of secondary defects, (n) all of these experimental results lead to the proposal of a new mechanism of deformation with glide elements which replace dislocations, under the condition of extremely high internal stress. Investigation of high-speed deformation achieved the strain rate of 10^7/s, and (o) Defect structures were found to change drastically by the deformation with strain rate over 10^5/s. Less