The characterization of dislocation loops in neutron irradiated zirconium

Experimental study and numerical modelling of the irradiation damage recovery in zirconium alloys

“…The tendency is that the interstitial loops are rapidly annealed during the heat treatment whereas vacancy loop annealing occurs slowly, leading progressively to a microstructure only composed of large vacancy loops in very low densities. These results are in good agreement with the results presented by Kelly and Blake [18] who have shown that the interstitial loops disappear during annealing.…”

“…The values of the computed vacancy super-saturation as a function of the computed critical diameter are compared to the Eq. (18) given by the recovery theory (Fig. 11).…”

“…The evolution of these two types of loops has been studied by TEM using the inside/outside contrast method [18,21,22]. The zone axis used for this study is B ¼ h1 1 2 3i and the diffraction vector used is g ¼ 1 2 1 2.…”

“…Also heat treatments lead to the annealing of the radiation induced loops [17,18]. However, this phenomenon has usually not been studied for similar duration and temperature as for the creep tests.…”

Irradiation Induced Defect Clustering in Zircaloy-2

“…In Zr alloys, prismatic (<a>-type) dislocation loops are the basic and most well-known component of radiation damage structures and are observed in a wide range of irradiation temperatures (80-500 • C) [2]. These loops are visible at lower to higher neutron doses, with densities saturating at relatively low doses, and have been extensively studied by neutron, charged particle irradiation, and MD simulations [2][3][4][5][6][7][8]. It has been reported that the point-defect clusters formed in Zircaloy-2 at temperatures between 250 and 400 • C and for irradiation doses lower than 5 × 10 25 nm −2 (E > 1 MeV), which can be observed by using transmission electron microscopy (TEM) (>2 nm), and consist of perfect dislocation loops, either of vacancy or interstitial nature, with Burgers vector of temperature [9,10].…”