Characterization and corrosion behavior evaluation of nanostructured TiO2 and Al2O3-13 wt.%TiO2 coatings on aluminum alloy prepared via high-velocity oxy-fuel spray
In this study, nanostructured titania (TiO2; n-TO) and nanostructured alumina-titania (Al2O3-13 wt.%TiO2; n-ATO) coatings were successfully deposited on the 6061 aluminum alloy by applying the high-velocity oxy-fuel process. The n-TO coating showed limited pores or microcracks accompanied by both pa...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Published: |
Springer
2021
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| Subjects: | |
| Online Access: | http://eprints.utm.my/id/eprint/95537/ http://dx.doi.org/10.1007/s11665-020-05333-4 |
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| Summary: | In this study, nanostructured titania (TiO2; n-TO) and nanostructured alumina-titania (Al2O3-13 wt.%TiO2; n-ATO) coatings were successfully deposited on the 6061 aluminum alloy by applying the high-velocity oxy-fuel process. The n-TO coating showed limited pores or microcracks accompanied by both partially and fully melted areas within splats. The n-TO coating exhibited about 25% higher microhardness compared with the n-ATO coating. The agglomerated non-molten nanostructured TiO2 particles that are randomly dispersed and embedded within the n-TO coating microstructure act as arresters of cracks through either branching or blunting crack tips, resulting in about 17% higher bonding strength, as compared to the n-ATO coating with a looser microstructure. The n-TO coating demonstrated superior hardness, higher wear resistance, and smoother wear scar than the n-ATO and uncoated Al substrate. The electrochemical test indicated that the n-ATO coating had about a 50% higher corrosion rate than the n-TO coating because of its looser structure. The immersion test revealed that the n-ATO coating had been severely attacked by blistering and deep cracks corrosions, whereas limited attacks could be distinguished using the n-TO coating in the substrate interface. Based on the results, the n-TO coating can effectively protect the Al alloy substrate against 3.5 wt.% NaCl solution. |
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