Cerium-based conversion films developed on LiAl-layered double hydroxide coatings for corrosion protection of AA7075 aluminum alloys

Journal of Electrochemical Science and Engineering

article

Aurora Petica¹  Adrian Cristian Manea¹  Geanina Mihai¹  Ioana Nicola²  Victoria Ceara²  Liana Anicai¹ 

[1] Center of Surface Science and Nanotechnology, University Politehnica of Bucharest;ICPE-SA

关键词: Conversion coatings;    chromium-free conversion coatings;    aluminum alloys;    corrosion behavior;    hydrophobic layers;   

DOI  :  10.5599/jese.1305

学科分类：内科医学

来源: International Association of Physical Chemists (IAPC)

【 摘 要 】

The paper presents several experimental results regarding the influence of various procedures applied to incorporate Ce species in hydrotalcite–type chemical conver­sion coatings on the overall corrosion performance for AA 7075 aluminum alloy as a metallic substrate. Two routes were envisaged: (i) chemical incorporation of Ce by immersion in cerium nitrate solutions and (ii) electrochemical deposition of hydro­phobic Ce - based layer involving ethanolic solutions of stearic acid and cerium nitrate. The chemical route involving immersion in cerium nitrate solutions led to the incorpo­ration of 2.46 – 6.84 wt.% Ce in the composition of the porous conversion layer. The electrochemical process facilitated the formation of a hydrophobic cerium stearate layer on porous hydrotalcite conversion coating showing water contact angles of about 132o and a higher Ce content incorporated of 6.55 – 9.73 wt.%. The corrosion performance of the Ce-based conversion coatings is also discussed.

【 授权许可】

CC BY