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-----Trivalent finish for aluminum
Q. I have a customer that wants us to provide his parts with Trivalent finish. This part is made from 5052H32 Aluminum. Is this possible to do? If not, are there any alternative suggestions?
Sheet metal fabrication - Cedar Rapids, Iowa, United States
2005
This is a meeting place for camaraderie & sharing, not a free consultancy. So some readers don't engage with anonymous posters.
A. MIL-C-5541 Chromate conversion coating of aluminum utilizes hexavalent chromium solutions. Due to concerns about hexavalent chromate, an increasing number of suppliers offer proprietary trivalent treatments for aluminum or chrome-free treatments for aluminum. Finishing.com's supporting advertisers offer one or the other. You can locate them with a little browsing of our Chemicals Directory.
Articles have been printed in the technical journals purporting to prove that these products are the equal of hexavalent chrome treatments (although some disagree).
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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A. Chem. film has been around for years; it is used to protect and /or prepare aluminum for painting. The most successful ones were patterned after Iridite or Alodine which are trade marked names and contain hex chrome. Until recently trivalent chromates generally had little success replacing these materials. There is now a group of products that compare favorably with the hex chem. films. These should shortly be on the QPL list and meet or exceed the requirements of MIL-C-5541.
Drew Nosti, CEF
Anodize USA - Ladson, South Carolina
A. You can find very good free informations on next web page:
www.aluminum.org/TALAT/lectures/5202.pdf ⇩
Good luck!
- Cerovski vrh Croatia
2005
A. This link will get you there
http://www.aluminium.org/education/TALAT/lectures/5202.pdf ⇩
- Chennai, India
2005
[Ed. update: The above link is broken. Thankfully, the Internet Archive preserved a copy here 🙂.
Thanks for the info, folks. As long as we're listing links to reports on non-hex aluminum treatments, here's a couple more:
• New Zealand Trade and Enterprise Group (
• ESTCP Phase I Report Non-Chromate Aluminum Pretreatments
[Ed. update: The above links have broken. Thankfully, The Internet Archive preserved copies of those two documents here and here 🙂
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