Microstructure and Electrochemical Performance Evaluation of Zn, Zn-5 wt.% Al and Zn-20 wt.% Al Alloy Coated Steels
| Autor: | Monojit Dutta, M. Manna, A. N. Bhagat |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Passivation Alloy chemistry.chemical_element 02 engineering and technology Zinc engineering.material 01 natural sciences Corrosion symbols.namesake Coating Aluminium 0103 physical sciences General Materials Science 010302 applied physics Mechanical Engineering Metallurgy technology industry and agriculture equipment and supplies 021001 nanoscience & nanotechnology Microstructure Galvanization chemistry Mechanics of Materials engineering symbols 0210 nano-technology |
| Zdroj: | Journal of Materials Engineering and Performance. 30:627-637 |
| ISSN: | 1544-1024 1059-9495 |
| DOI: | 10.1007/s11665-020-05359-8 |
| Popis: | A comparative study has been done on three coatings obtained on steel surface using pure Zn, two Zn-Al alloy baths. The coatings obtained using both Zn alloy baths are thinner than the same obtained using pure zinc bath as Al reacts with steel and forms very thin layer of Fe2Al5 phase which hinders iron-zinc reaction. Coating obtained using pure zinc bath predominantly consists of eta (~ 100 wt.% Zn) and zeta (FeZn13) phases in combination with less extent of delta (FeZn10) and gamma (Fe3Zn10) phases, whereas coatings obtained using Zn-Al alloy baths exhibit zinc-rich phase covered by aluminum rich phase with Al2O3 at the top. Al-rich phase content is higher for Zn-20 wt.% Al alloy coating. The coatings obtained on steel surfaces using both the Zn alloy baths show better ductility compared to pure zinc bath. This can be attributed to the presence of brittle Zn-Fe alloy phase in the coating obtained using pure zinc bath. The coatings obtained using both the Zn alloy baths were found to have a greater passivation characteristics compared to the coating obtained using pure zinc bath without compromising sacrificial characteristic of the coating. Electrochemical and salt spray tests results showed 3 and 6 times improved corrosion resistance properties of Zn-5 wt.% Al and Zn-20 wt.% Al alloy coatings than the pure zinc coating. |
| Databáze: | OpenAIRE |
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