Microstructural development in a model austenitic alloy following electron and ion irradiation

In order to study the microstructural evolution of cascade and interaction between cascade and He, the irradiations were carried out using ion accelerator to introduce the cascade and a high resolution high voltage electron microscope (1250 kV) to irradiate with electrons and for in situ observation. A lot of small cascades were introduced by Ni+-ion irradiation at room temperature, and due to following electron irradiation at higher temperature interstitial type dislocation loops were nucleated from the interstitials rich zone and grew. On the other hand the cascades transferred to SFTs during annealing above 623 K. When He atoms were previously implanted, He bubbles were formed at cascades. Also segregation of solutes and precipitates were induced at cascades during electron irradiation.