주조용 알루미늄 합금의 천연해수 내 전기화학적 및 캐비테이션-침식 특성

• Published in: Corrosion science and technology Vol. 23; no. 5; pp. 437 - 448
• Main Authors: 박일초, Il-cho Park, 황현규, Hyun-kyu Hwang, 신동호, Dong-ho Shin, 김성종, Seong-jong Kim
• Format: Journal Article
• Language: Korean
• Published: 한국부식방식학회 31.10.2024
• Subjects: Cast aluminum alloy; Cavitation-erosion; Corrosion; Hardness; Seawater; 금속공학; Corrosion; Cast aluminum alloy; Hardness; Cavitation-erosion; Seawater
• ISSN: 1598-6462; 2288-6524
• DOI: 10.14773/cst.2024.23.5.437

This study investigated electrochemical and cavitation-erosion characteristics of three types of cast aluminum alloys in natural seawater. Electrochemical properties were evaluated by calculating corrosion potential and corrosion current density through a potentiodynamic polarization experiment in a static marine environment. Cavitation-erosion characteristics were determined by measuring surface roughness, maximum damage depth, weight loss and surface damage shape with experiment time. Indentation experiments revealed that surface hardness values of domestic products were higher than those of foreign products due to high contents of zinc, magnesium and copper. This is because zinc, magnesium and copper dissolved in the aluminum crystal lattice could transform the lattice structure. Due to increased surface hardness, domestic products showed the best cavitation-erosion resistance. However, their corrosion resistance were found to be relatively poor. This is due to formation of galvanic couples within the alloy when zinc, magnesium and copper are present in relatively high concentrations, which can accelerate corrosion.