Improvement of corrosion resistance of 6063 aluminum alloy by selective removal of intermetallic compound phases

Abstract

Attempts have been made to improve corrosion resistance of Al–Mg–Si alloy 6063 by an electrochemical treatment. We have found that the intermetallic compounds exposured on the 6063 alloy specimen have been preferentially and selectively removed by cathodic current of −2 kA·m⁻² for 300 s in a 20 mass% H₂SO₄ solution. Above treatment leads to experimental results that the 6063 alloy specimens, which have had free intermetallic compounds and anodized in a 20% H₂SO₄ solution, show excellent corrosion resistance in a NaCl solution.