Cel
"Generally, most magnesium alloys have higher bare corrosion rate than aluminium. Therefore, the role of surface protection is very important in design of magnesium aircraft components.
FP6 project AEROMAG showed that modern surface treatment technologies, such as PGA ALGAN 2M, MAGOXIDE, MAGPASS and Gardobond X4729 offer high protection level for magnesium components. The results are very close to those of coatings on aluminium.
It is well-known that magnesium has galvanic corrosion with any other metal. Therefore it's impossible to use metallic layers on magnesium as conductive coatings. The option is to build thin chemical conversion layers which have low electrical resistance.
For many years, such conductive coatings were built on base of Cr VI compounds. The examples of such treatments are Dow-19 and NH35.
Due to environmental restrictions, Cr VI shall be replaced. Chemical conversion coatings on the base of Cr III are marked as potential replacement of Cr VI processes on aluminium. However, performance of Cr III processes on magnesium is very low. Modern alternative to Cr VI treatments are silanes. Silane protective coatings are based on ability of hydrolysed silanes to build bonds with metallic substrate. Silane treatments are environmentally friendly and cost effective due to low concentration of active compound (usually 1-5%), short process sequence, low energy and water consumption and they do not have galvanic corrosion with magnesium. They can be applied by immersion, spraying or locally (touch up). The important advantage of silane coating technology is precise control for coating thickness.
Therefore, in order to approach high corrosion resistance with electrical conductivity, the development will be focused on silane structure rather than on coating thickness. In the frame of the development, structure of proprietary silane will be modified to increase number of hydrolysed groups and to introduce additional, chemical stable functional groups."
Dziedzina nauki
- natural sciencesphysical scienceselectromagnetism and electronics
- natural scienceschemical sciencesinorganic chemistryalkaline earth metals
- engineering and technologymechanical engineeringvehicle engineeringaerospace engineeringaircraft
- natural scienceschemical sciencesinorganic chemistrypost-transition metals
- engineering and technologymaterials engineeringcoating and films
Zaproszenie do składania wniosków
SP1-JTI-CS-2011-02
Zobacz inne projekty w ramach tego zaproszenia
System finansowania
JTI-CS - Joint Technology Initiatives - Clean SkyKoordynator
18960 En Harod Ihud
Izrael