The Effects of Different Sealing Techniques for Anodic Film of Al-12.7Si-0.7Mg Alloys

摘要

Al-12.7Si-0.7Mg is a novel kind of high silicon aluminum alloy and urgently in need of surfacetreatment technologies. Optimal processing parameters of stearic acid sealing treatment wereinvestigated by evaluating the weight loss of anodic film. The anodic films were sealed by other foursealing methods of boiling water sealing, nickel acetate sealing, chromate sealing and cold nickelfluoride sealing in order to compare with stearic acid sealing. Surface morphology of anodic oxidefilms after sealing treatment showed that stearic acid sealing specimens were smooth, uniform andcompact. The results of potentiodynamic polarization, phosphorus-chromium acid oxide method andalkaline etching test indicated that stearic acid sealing was more highly effective and environmentallyfriendly and exhibited excellent corrosion resistance.