Electrochemical corrosion behavior of Zr-based alloy treated by short-pulse laser radiation

Zirconium is widely used in nuclear plants because it has unique properties including irradiation and corrosion stability. In this paper we studied influence of structure and phase content on anticorrosion properties of Zr-based alloy subjected by laser short-pulse treatment. It was shown that laser irradiation promotes formation of thin protective layers on the alloy E110 with very high anticorrosion properties in neutral and aggressive media. Structure of samples was investigated using x-ray spectroscopy, scanning and transmission electron microscopy and x-ray photoelectron spectroscopy. According to the results of the study surface layers consist from oxide nanoparticles dispersed in the metal matrix. Laser short-pulse treatment of zirconium surface in protective environment of argon lead to surface modifications that responsible for the improvement of protective properties of the surface. Even higher protective properties in the terms of electrochemical corrosion resistance were obtained by laser treatment in the air. High speed laser sintering allows to obtain high density protective oxide layers formed by high temperature interaction between oxygen and zirconium. As a result a metal matrix composite layers are formed which consists of nanosized inclusions of zirconium oxides in the metal matrix. High temperature developed in the irradiated area provides active interaction between oxides and zirconium, which is responsible for appearance of the good interface bonding between the matrix and inclusions. These factors improve electrochemical corrosion resistance sharply.