Field ion microscopy of metal interfaces after radiation exposure

Abstract

Based on the results obtained by the field ion microscopy method, the atomic structure of the boundary region of metal interfaces after various radiation exposures has been analyzed. In the process of studying the atomic structure of planar defects in metallic materials after irradiation with accelerated Ar+ ion beams up to an energy of E = 30 - 40 keV and fast neutrons by a fluence of F = 6.7 ·1022 m-2, a different atomic structure of their boundary region has been revealed. It has been shown that in Pd50Cu30Ag20 alloys (wt.%) and Cu3Au alloys after the structural phase transformations initiated in them by ion irradiation (Ar+ ion beams), the width of the boundary region of interphase metallic interfaces corresponds to the width of the boundary region of interphase boundaries in these alloys after thermal and thermo mechanical treatments. It has been found that the width of the boundary region of metal interfaces varies depending on the type of radiation exposure and the metallic material under study. It has been experimentally demonstrated that in metallic Pt, both after irradiation with fast neutrons with a fluence of F = 6.7 ·1022 m-2, and after exposure to gas ion beams (Ar+) accelerated to 30 keV, fluence (F) - 1016 ion / m2 and ion current density j = 200 µA / cm2, the boundary region has inclusions of the vacancy cluster type, but with the presence of a certain number of atoms of the material. The evaluation of such inclusions shows that these are ellipsoidal formations with a width of no more than 3 - 4 nm and a length of about 5 nm. It is established that the parameters of the interphase interfaces of solid solutions, which are the result of irradiation, are identical to the parameters of the interphase boundaries formed after thermal treatments. © 2019, Institute for Metals Superplasticity Problems of Russian Academy of Sciences. All rights reserved.