Dislocation movement through ultra-fine obstacles in a thermally aged Fe–Cu alloy was studied by in situ transmission electron microscope observation. A very effective technique for quantitative estimates of radiation embrittlement was proposed. The obstacle strength was estimated from the critical bow-out angle of the dislocations. The increase in shear stress, which was estimated from the averaged strength of ultra-fine obstacles and the averaged distance between the two neighboring obstacles on a dislocation in the in situ observation, was in good agreement with the hardening obtained from macroscopic mechanical tests. This technique was very useful to predict the mechanical properties of irradiated fusion and fission reactor materials from the microstructure obtained from experimental observations and/or the computer simulations.

In situ TEM Observation of Dislocation Movement through the Ultrafine Obstacles in an Fe Alloy. K.Nogiwa, T.Yamamoto, K.Fukumoto, H.Matsui, Y.Nagai, K.