Influence of Na₂SO₄-Electrolyzed Reduced Water on the Surface of Pure Aluminum

Abstract

This paper describes the influence of Na₂SO₄-electrolytic reduced water (hereinafter referred to as ER water) on pure aluminum. First, the etching action of Na₂SO₄ ER water on the surface of pure aluminum was clarified by the etching test using immersion. The comparative study showed that Na₂SO₄ ER water was superior to chemical solution or Na₂SO₄-electrolytic oxidizing water in etching action, and the stronger electrolytic current value becomes, the stronger the etching action of Na₂SO₄ ER water becomes. Next, by the observation using FE-SEM image, the influence of Na₂SO₄ ER water on the micro shape of the surface of pure aluminum was clarified. The results showed there was not a difference between the micro shape of the sample piece done by Na₂SO₄ ER water and the one done by NaOH solution, and even in either case the alien substance appears on the surface of sample pieces. Lastly, by analyzing the surface using EDS, the influence of Na₂SO₄ ER water on the chemical composition of the surface of sample pieces was clarified. The results showed Na₂SO₄ ER water and NaOH solution are similar level. By this study, we received the suggestion that Na₂SO₄ ER water could be applied to the surface treatment such as the etching of pure aluminum.