Chrome-Free Passivation

Hello every body

I am a student of coatings technology and I am working on a project on passivation in automotive industry.

In my country we have chrome-free passivation and instead of chromium acids we use zirconium salts.

Could anyone help me on the mechanism of this process?

Dear Mr. Razavi-

Zirconium along with other film formers will passivate zinc, the result is a clear and not very corrosion resistant finish. How many hours of salt spray does your zirconium provide?

Regards,

Hello:

I'm a chemical engineering student working on my end of degree project. It would be very useful for me if somebody could give me some information about the free-chromium passivation process in the automotive industry using titanium salts. Topics like mechanism, cost, effluent treatment and required modifications for using titanium on a chromium passivation process are what I'm looking for.

Thank you,