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 -2kA·m-2 for 300s 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.