Study on Corrosion Behavior of Porous Pure Copper Based on Electrochemistry and Scanning Kelvin Probe

Abstract

Porous metals are widely used in filtration and separation, flame retardant explosion-proof, biomedical application, etc. Compared with its corresponding dense metal, the presence of porous structures also leads to different corrosive performances in porous metal. Some studies have utilized the weight loss method, electrochemical impedance to evaluate porous metal corrosion behavior; however, the influence of pore structure on metal corrosion is still ambiguous, and present methods used for analyses of porous metal corrosion are statistical averages of the corrosion behavior of the entire porous material, which cannot accurately reflect the corrosion behavior inside the pores. Herein, we prepare the porous copper samples with 0, 24, 72, and 96 pores using a mechanical process, and employ scanning Kelvin probe combined with electrochemical polarization and impedance spectroscopy to test the corrosion performance of the porous copper in static and dynamic NaCl solutions. The relevant results indicate that in the static solution, the corrosion resistance of the samples gradually increases with the rise in the number of pores. By contrast, in the dynamic solution, the 24-pore sample is more susceptible to corrosion than the sample without the pore.