ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The different chrome-free chemical conversion coatings were prepared on AZ91Dmagnesium alloy and SEM was used to observe the surface. The corrosion behaviors of die-castingAZ91D magnesium alloy with different coating in chloride environment were investigated byhydrogen gas evolution in immersion test, salt spray test and electrochemical measurement. Theresults showed that the corrosion resistance of magnesium alloy treated with two-step chemicalconversion and sealing was the highest and was comparable with that of chromating, and followedby two-step chemical conversion treatment without sealing. The one-step chemical conversiontreatment had the lowest corrosion resistance. Polarization and EIS characteristics in 5% NaClsolution depended on the type of surface treatment and correlated well with the order of corrosionresistance. Contrasted with one-step chemical conversion coating, the coating of two-step chemicalconversion with sealing on magnesium alloy had more excellent corrosion resistance because the |Z|increased, the corrosion area was decreased and the time of the first pitting occurrence wasprolonged. It is expected that this experiment can provide a foundation for designing more superchemical conversion coating to replacing the chromate conversion
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.15-17.473.pdf
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