in order to study the effect of copper ion implantation on the aqueous corrosion behavior, samples of zircaloy-4 were implanted with copper ions with fluences ranging from 1 x 10(16) to 1 x 10(17) ions/cm(2), using a metal vapor vacuum arc source (MEVVA) operated at an extraction voltage of 40 W The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), respectively. Glancing angle X-ray diffraction (GAXRD) was employed to examine the phase transformation due to the copper ion implantation. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zircaloy-4 in a 1 M H2SO4 solution. It was found that a significant improvement was achieved in the aqueous corrosion resistance of zircaloy-4 implanted with copper ions when the fluence is smaller than 5 x 10(16) ions/cm(2). The corrosion resistance of implanted samples declined with increasing the fluence. Finally, the mechanism of the corrosion behavior of copper-implanted zircaloy-4 was discussed. (c) 2005 Elsevier B.V. All rights reserved.