Speaker
Description
Aluminum is an excellent choice for structural applications in the aerospace industry due to its high strength-to-weight ratio. Aluminum alloys, especially high strength alloys, are however susceptible to corrosion and surface treatments are hence required to withstand the harsh environment of an aircraft.
Since 2017, the use of hexavalent chromium in surface treatments has been prohibited due to its toxicity to humans and the environment. Thus, the need for environmentally sustainable alternatives is urgent. Tartaric sulfuric acid anodization is a commonly used alternative to chromic acid anodizing. The corrosion resistance of high strength alloys provided by anodization is however not enough if not combined with further treatments such as painting or sealing where the latter is also commonly performed using chromate containing treatments.
Therefore, we present a nano-based rare-earth sealing to provide enhanced corrosion protection of the anodic coating. A cerium salt penetrates the pores of the anodic coating and when combined with hydrogen peroxide, small nanoparticles are formed inside the pores producing a sealed coating.
When the sealing is performed through a novel aerosol-based wet thin film coating technique, the surface treatment can be performed in a closed chamber without the need of large surface treatment baths. In addition to the reduced usage of hexavalent chromium, this technique also offers the opportunity to decrease the consumption of chemicals providing an environmentally sustainable surface treatment for aluminum alloys.
| Speaker Country | Sweden |
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