Metal finishing Q&As since 1989

-----

What is Altizizing?

2006

Hi!
My name is Björn Ljungström and I'm interested to know more about the alternative processes for traditional chromium(IV) treatments.


How many different chrome free solutions are there on the market today?

What exactly are the differences between chromium III and chromium VI

When I was "googling" around I saw a method called Altizizing, what can you guys tell me about this method/process?
What are for example the differences between Altizizing and Chromital?

Do you think that there are going to be some restrictions concerning chromium III in the future?

Is EU planning on a new Rohs directive soon?

Thankful for your help!

Sincerely,

Björn Ljungström

---

2006

I won't guess at the number of Cr-free processes, but note the emphasis on eliminating hexavalent Cr, not trivalent Cr. Hexavalent Cr is a powerful oxidizer and carcinogen. Trivalent Cr is less toxic; perhaps only 1/100 as harmful (my guess, not a medical opinion). In fact, trivalent Cr is an essential trace nutrient.

ChromitAL TCP is SurTec International's licensed, trivalent chromium product satisfying MIL-DTL-81706 and MIL-C-5541 requirements for corrosion resistance, electrical conductivity and paint adhesion.

Altizizing is a patented, non-chromium coating process for 'most aluminum and magnesium alloys' from Altitec (http://www.altitech.se). Results are promising, and it is said to produce a yellow coating from a manganese solution at ambient temperature, but only 168 hours neutral salt spray resistance on an unspecified Al alloy is mentioned (1000 hours painted). Perhaps you can test it and report results.

There are restrictions on trivalent Cr with respect to wastewater discharge and air pollution (but not nearly as severe as for hex. Cr), and I doubt that its use will ever be banned.

California (computer monitors & TVs) and China (internal, non-export items) have new RoHS laws. I am not familiar with pending EU legislation.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.