한국표면공학회지 (49권5호 395-400)
Effect of Fluoride Conversion Coating on the Corrosion Resistance and Adhesion of E-painted AZ31 Magnesium Alloy
Fazal, Basit Raza;Moon, Sungmo;
Surface Technology Division, Korea Institute of Materials Science;
This article reports improved corrosion resistance and adhesion of electro-paint (E-paint) with fluoride conversion coating (FCC) on AZ31 Mg alloy for the first time. These improvements were observed in comparison to chemically polished samples with no chemical conversion coating and samples with cerium conversion coatings (CeCC). FCCs were prepared in a hydrofluoric acid (HF) solution for four different times; 10, 30, 60, and 120 s. The colour of the samples changed from light gold to brown with increasing immersion time, indicating the formation of thicker FCC coatings with increasing immersion time. The adhesion of the E-paint on FCC-coated AZ31 Mg alloy was tested after 500 h of immersion in deionized (DI) water. Salt spray test (SST) results revealed delamination of E-paint on the chemically polished sample, severe blistering on the samples with CeCC, but no delamination and no blistering on the samples with FCC.
Fluoride conversion coating;AZ31 Mg alloy;Corrosion resistance;Adhesion of E-paint;Salt spray test;