Abstract
Plasma electrolytic oxidation (PEO) is a surface treatment technology mostly applied to some metallic materials, such as Al, Ti or Mg. Generally, the process is conducted in aqueous electrolyte solution in parts of limited dimensions due to the heating-up the system. It was previously shown that this issue could be solved in the process takes place in molten salt. In the presented comparative research, the PEO process is conducted in silicate electrolyte and nitrate molten salt. Aluminum oxide coatings were obtained on Al 1050 alloy in both processes and examined by optical and electron microscopy, EDS, XRD, micro-hardness and corrosion resistance measurements. Obtained results illustrated that the created coating in the process conducted in molten salt consists of hard α-Al2O3 and ɣ-Al2O3, has no additional compounds and through pores and shows higher corrosion resistance than coating formed in silicate electrolyte. Coating formed in PEO in aqueous electrolyte solution consists of η-Al2O3 and amorphous SiO2 in addition to hard α-Al2O3 and ɣ-Al2O3 phases, has through pores and shows lower corrosion resistance.
Original language | English |
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Pages (from-to) | 590-595 |
Number of pages | 6 |
Journal | Surface and Coatings Technology |
Volume | 344 |
DOIs | |
State | Published - 25 Jun 2018 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2018 Elsevier B.V.
Funding
This work was carried out with the support of the Ministry of Aliyah and Integration, the State of Israel . Additionally, the authors would like to thank Ms. Natalia Litvak from the Engineering and Technology Unit at the Ariel University for her help with electron microscopy investigations.
Funders | Funder number |
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State of Israel |
Keywords
- Aluminum alloy
- Aqueous solution electrolyte
- Molten salt electrolyte
- Plasma electrolytic oxidation (PEO)