Corrosion Protection of Magnesium Alloys via Diffusion Coatings by the Slurry Coating Methode
Heinemann, Peter (2015)
Heinemann, Peter
2015
Master's Degree Programme in Science and Bioengineering
Luonnontieteiden tiedekunta - Faculty of Natural Sciences
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Hyväksymispäivämäärä
2015-08-14
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201507291447
https://urn.fi/URN:NBN:fi:tty-201507291447
Tiivistelmä
This thesis investigates the creation of diffusion layers by the slurry coating method using Al and Zn powders on AZ31 and AZ91. The method was applied at 450°C, 420°C and 380°C in an $Ar/H_{2}$. Secondary electron microscopy, backscattered electron microscopy, energy dispersive x-ray spectroscopy (EDX) and potentio dynamic measurements were used to classify the diffusion layers. Diffusion coatings were successfully produced at a temperature of 450°C for a Zn slurry and a mixed Al-Zn slurry. These diffusion layers were in general rich on zinc and several hundred $\mu m$ thick. Electrochemical measurements showed that $E_{corr}$ became more anodic by a zinc rich diffusion layer, but $i_{corr}$ did not change. All in all, it could be shown that diffusion layers could be produced by the slurry coatings method for Zn and Al-Zn slurries and opportunities for further process optimisations addressed.