注氢纯铝中间隙型位错环一维 迁移现象的原位观察

During the high-energy particle irradiation of nuclear fusion reactor materials, a large number of point defects are generated, leading to phenomena such as irradiation embrittlement and irradiation swelling. Therefore, it is of great significance to study the evolution process of point defects during irradiation. The one-dimensional migration phenomenon of point defect clusters is one of the main research contents of this evolution process. In this paper, a common low-voltage (200 kV) transmission electron microscope was used to observe and analyze the one-dimensional migration phenomenon of interstitial dislocation loops in hydrogen-implanted pure aluminum under electron irradiation at room temperature. Under 200 keV electron irradiation, multiple dislocation loops in hydrogen-implanted pure aluminum can simultaneously undergo one-dimensional migration, or a single dislocation loop can independently carry out one-dimensional migration. The dislocation loops can perform one-dimensional long-range migration on a micron scale along the direction of the Burgers vector 1/3, and the one-dimensional migration along the direction of the Burgers vector 1/2 can also reach several hundred nanometers. The concentration gradient of interstitial atoms generated during electron beam irradiation is the reason for the one-dimensional migration of dislocation loops and determines their migration direction. When a dislocation loop undergoes rapid one-dimensional migration, a moving track will be left behind; the faster the one-dimensional migration rate of the dislocation loop, the longer the moving track. These moving tracks will gradually disappear within tens of seconds after the migration is completed.

核聚变堆材料在高能粒子辐照过程中会产生大量点缺陷,导致辐照脆性和辐照肿胀等现象.因而,研究.点缺陷在辐照过程中的演变过程至关重要.点缺陷团簇的一维迁移现象是这种演变过程的主要研究内容之.一.本文采用普通低压 (200kV) 透射电镜,在室温条件下对注氢纯铝中的间隙型位错环在电子辐照下的一维.迁移现象进行了观察和分析.在 200keV 电子辐照下,注氢纯铝中的位错环可多个、同时发生一维迁移运动,.也可单个、独立进行一维迁移运动.位错环沿柏氏矢量 1/3 的方向可进行微米尺度的一维长程迁移,沿.柏氏矢量 1/2 的方向一维迁移也可达数百纳米.电子束辐照时产生的间隙原子浓度梯度是引起位错环一.维迁移并决定其迁移方向的原因.位错环发生快速一维迁移时,其后会留下一条运动轨迹;位错环一维迁移.的速率越快,运动的轨迹则越长,在完成迁移过后的几十秒内这些运动轨迹会逐渐消失.