Anodic behavior of metallic electrodes during cyclic deformation in aqueous solutions by holographic interferometry 'holometry'

摘要

A fundamental investigation on the influence of static and cyclic deformation on the anodic dissolution behavior, i.e., corrosion, of metallic electrodes in aqueous solution has been conducted. The investigation was successful in developing a novel experimental method for studying the effects of deformation on corrosion. The development of the new method is based on incorporating electrochemical techniques with those of holographic interferometry. The new method is capable of measuring microscopic deformation and the anodic dissolution current of electrodes surface, simultaneously. Along with this method, theoretical models were developed. The models are able to describe the corrosion current density of electrodes under the influence of applied loads or applied load and potentials.;The new experimental method has been successfully used to obtain data on two metallic systems. The systems are Molybdenum in 0.75N KCl and Nickel in 1N H$sb2$SO$sb4$. Both of these metals were tested in annealed and as-received conditions in different modes of applied loads. The deformation which occurred in molybdenum and nickel systems were as results of fixed grips, constant load, and cyclic load. In addition, the experimental method has failed to provide data on Aluminum in 1N NaCl and Copper in 1N H$sb2$SO$sb4$ + CuSO$sb4$. The reason for not obtaining the data in aluminum and copper systems was due to the development of a thick oxide layer or dense reaction products on the surface of the metal.;In both systems of molybdenum and nickel, the cyclic deformation stimulates higher effect on the corrosion current density than that of static deformation except in the as-received molybdenum case in the stress corrosion test under fixed grips mode. In this test, the corrosion current density was observed to have a higher value than the corrosion current density in the corrosion fatigue test after the wire deformed 9 $mu$m.;A lack of experimental data in the stress corrosion test under the constant load for the as-received molybdenum and as-received nickel as well as the lack of data in the corrosion fatigue test for the annealed nickel, led to suggest that the apparatus of the loading lever was not quite stable during these tests. (Abstract shortened with permission of author.).