Influence of Solvent and Electrical Voltage on Cathode Plasma Electrolytic Deposition of Al2O3 Antioxidation Coatings on Ti-45Al-8.5Nb Alloys

Xu Yang; Zhipeng Jiang; Xianfei Ding; Guojian Hao; Yongfeng Liang; Junpin Lin

doi:10.3390/met8050308

Metals (May 2018)

Influence of Solvent and Electrical Voltage on Cathode Plasma Electrolytic Deposition of Al2O3 Antioxidation Coatings on Ti-45Al-8.5Nb Alloys

Xu Yang,
Zhipeng Jiang,
Xianfei Ding,
Guojian Hao,
Yongfeng Liang,
Junpin Lin

Affiliations

Xu Yang: State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
Zhipeng Jiang: State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
Xianfei Ding: Cast Titanium Alloys R&D Center, Beijing Institute of Aeronautical Materials, Beijing 100095, China
Guojian Hao: Beijing Research Institute of Mechanical & Electrical Technology, Beijing 100083, China
Yongfeng Liang: State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
Junpin Lin: State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China

DOI: https://doi.org/10.3390/met8050308
Journal volume & issue: Vol. 8, no. 5
p. 308

Abstract

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Al2O3 coatings were prepared on Ti-45Al-8.5Nb alloys via cathodic plasma electrolysis deposition (CPED) in both 1.2 M Al(NO3)3 aqueous and ethanolic solutions. Different voltages were also applied during the deposition process to optimize coating properties. Coatings deposited in both solutions mainly consisted of γ-Al2O3, with some Al(OH)3 found in coatings prepared in aqueous solution. Coatings prepared in ethanol solution exhibited better oxidation resistance at 900 °C as well as better substrate adhesion, which was mainly due to smaller crater sizes on coating surfaces. The deposition process was discussed in detail and the reason for the smaller craters examined. The results suggested that solution surface tension mainly influenced the average diameter of hydrogen bubbles that formed on cathode surfaces during the process. Smaller bubbles lead to both lower current densities on cathodes and smaller crater sizes on coatings.

Published in Metals

ISSN: 2075-4701 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Mining engineering. Metallurgy
Website: http://www.mdpi.com/journal/metals

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