Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (51권6호 421-429)

Electrochemical Corrosion Damage Characteristics of Aluminum Alloy Materials for Marine Environment

해양환경용 알루미늄 합금 재료의 전기화학적 부식 손상 특성

김성진;황은혜;박일초;김성종;
Kim, Sung Jin;Hwang, Eun Hye;Park, Il-Cho;Kim, Seong-Jong;

순천대학교 신소재공학과;목포해양대학교 기관시스템공학부;
Department of Materials Science and Engineering, Sunchon National University;Division of Marine Engineering, Mokpo National Maritime University;

DOI : 10.5695/JKISE.2018.51.6.421

Abstract

In this study, various electrochemical experiments were carried out to compare the corrosion characteristics of AA5052-O, AA5083-H321 and AA6061-T6 in seawater. The electrochemical impedance and potentiostatic polarization measurements showed that the corrosion resistance is decreased in the order of AA5052-O, AA5083-H321 and AA6061-T6, with AA5052-O being the highest resistant. This is closely associated with the property of passive film formed on three tested Al alloys. Based on the slope of Mott-Schottky plots of an n-type semiconductor, the density of oxygen vacancies in the passive film formed on the alloys was determined. This revealed that the defect density is increased in the order of AA5052-O, AA5083-H321 and AA6061-T6. Considering these facts, it is implied that the addition of Mg, Si, and Cu to the Al alloys can degrade the passivity, which is characterized by a passive film structure containing more defect sites, contributing to the decrease in corrosion resistance in seawater.

Keywords

Electrochemical experiment;Al alloy;Corrosion;Seawater;