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Passivation of coloured titanium

2000

I need to know different methods to passivate (anodized) coloured titanium. The problem is how to get the coulor more scratch resistant and better against corrosion. We have tried hot water without any improvement. We are (anodizing) couloring in manganese sulphate.

Does anybody know better methods?

Regards J˙rgen

J˙rgen Pettersson
- sweden

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2000

Color on Ti is very thin. It is an oxide, so it is very passive as it is.

Since the coating is very thin, it has very little "wear" resistance. Changing the temperature and concentration of the solution or changing the solution to another may give a slight increase. In aluminum, hard anodizing achieves some of its wear resistance by the colder temperature giving tighter pores.

It is going to take a lot of trial and error testing.

Basically, Ti anodize is for cosmetic purposes such as jewelery and parts identification.

James Watts
- Navarre, Florida

The anodizing you are referring to is a color produced by light interference; there is no real color, the oxide is transparent. You "see" the color because of a shift in the light wavelength as the reflection of light from the air/oxide verse the oxide/metal interface. As such the oxide is really thin..about 25-30 angstroms per volt applied. 250,000 of the little suckers = 0.001" So as far as a good wear coating, forget it! Good for jewelry but use it for ear rings not watch bands!

Now for anodizing for adhesive bond coating, very different. Also different "Tiodize" also called hard titanium anodize also ASM2488C very different. I am looking at it and if anyone can offer advise lets talk $$$$$.

Jon Quirt
- Fridley, Minnesota
2000