What does passivation mean?
The formation of a (oxide) film to cover the material and prevent further oxidation.
What are the steps in forming a passive film?
chemisorption of O2
splitting of the absorbed O2 -> Oads
formation of chargedn Oads -
intrusion of metal ions into adsorbed layer
growth of 3 dim oxide
What is the structure of passive films?
either monolayer: defective oxide (more amorphous than crystalline) layer
or bilayer: defective oxide, outer layer of reacted metal cations
very thin (one/two layer) hydroxyl group on both outer surfaces
What is the primary passivation potential?
How does the corrosion rate behave along this line?
What are the cathodic reactions in aereated, neutral, acidic solutions?
aereated:
neutral:
acidic:
Zuletzt geändertvor 5 Monaten
