HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
News
Materials & Assembly
Aluminum Aerospace Coating May Replace Toxic Chromates
11/15/2012

A materials engineering research team at the University of Nevada, Reno has developed an environmentally friendly, self-healing coating for aluminum that could replace toxic chromates.   (Source: University of Nevada, Reno/Mike Wolterbeek)
A materials engineering research team at the University of Nevada, Reno has developed an environmentally friendly, self-healing coating for aluminum that could replace toxic chromates.
(Source: University of Nevada, Reno/Mike Wolterbeek)

Return to Article

View Comments: Oldest First|Newest First|Threaded View
Page 1/2  >  >>
Charles Murray
User Rank
Blogger
Cost?
Charles Murray   11/15/2012 6:00:35 PM
NO RATINGS
Ann, any idea how this coating would compare, cost-wise?

Rob Spiegel
User Rank
Blogger
Nice development
Rob Spiegel   11/15/2012 8:08:54 PM
NO RATINGS
Good story, Ann. It's good to see an environmentally friendly substance to replace the toxic coating. I also liked the "cool video."

TJ McDermott
User Rank
Blogger
6061?
TJ McDermott   11/16/2012 10:50:18 AM
NO RATINGS
Ann, you noted 7000 series and 2024 series specifically.  Will this process work for all aluminum alloys?

Dave Palmer
User Rank
Platinum
Non-chromate coatings
Dave Palmer   11/16/2012 11:18:33 AM
NO RATINGS
@Ann: Thanks for a good article on a timely topic.  It would be interesting to see polarization curves and salt spray testing results for the molybdate coatings.

There is a wide variety of non-chromate conversion coatings, including permanganates, zirconates, titanates, cerates, and others.  There are also conversion coatings based on trivalent chromium.  Some of these have been around for many years, while others are newer.  However, to the best of my knowledge, none of them provide corrosion resistance that is quite as good as that of hexavalent chromate.

Electrodeposited coatings can meet or exceed the performance of chromate, but it is challenging to coat internal passages with electrodeposited coatings, and they don't have the self-healing characteristics of conversion coatings.

The U.S. military has a great on-line database with information about alternatives to chromate conversion coatings.

Ann R. Thryft
User Rank
Blogger
Re: Cost?
Ann R. Thryft   11/16/2012 11:41:33 AM
NO RATINGS
Chuck, I wish we could get more cost info on some of these new technologies. As usual, not much is known yet until it's in use in industrial quantities. OTOH, the fact that it's non-toxic may be worth a cost differential.

Dave Palmer
User Rank
Platinum
Re: 6061?
Dave Palmer   11/16/2012 1:53:35 PM
NO RATINGS
@TJ McDermott: The same thing that makes 7075 and 2024 so much stronger than other aluminum alloys also makes them less resistant to corrosion: copper.  The copper-containing intermetallic particles that are responsible for these alloys' high strength create tiny galvanic cells within the material itself.

In general, if you can protect 7075 and 2024 against corrosion, 6061 will be easy.

Ann R. Thryft
User Rank
Blogger
Re: 6061?
Ann R. Thryft   11/16/2012 3:29:57 PM
NO RATINGS
TJ, I mentioned those specific alloys because the sources did, as the coating was developed specifically for mil/aero applications. But they also stated that this coating works on "all aluminum products." That sounds like all aluminum alloys.

Scott Orlosky
User Rank
Platinum
Re: Cost?
Scott Orlosky   11/18/2012 7:07:46 PM
NO RATINGS
Good discussions.  Non-toxic alternatives to chromate coatings of aluminum can move us closer to the overall environmental objectives of such programs as RoHS. Looking at overall lifecycle costs is important when considering a process change as you noted. Chromates consume resources in the disposal of spent coating residues.

Ann R. Thryft
User Rank
Blogger
Re: Non-chromate coatings
Ann R. Thryft   11/19/2012 12:27:41 PM
NO RATINGS
Thanks, Dave, for the summary and all those links. Performance is often the main issue with environmentally friendly substitutes, whether it's coatings or fuel, that are candidates for replacing toxic ones. This one sounds like it's pretty close.

Lee Wolfel
User Rank
Iron
Re: Non-chromate coatings
Lee Wolfel   11/29/2012 9:38:19 AM
NO RATINGS
Hi Ann,

 

As a manufacturer of aluminum connectors for harsh environments the subject of what coating to use for corrosionprotection is a constant.  Especially today with RoHS and REACH activities.  Needless to say I am imensely interested and was hoping you can provide contact information for Chidambaram or a path to learn more?

 

THANKS,

Lee

Page 1/2  >  >>
Partner Zone
Latest Analysis
We searched far and wide for the top employers for engineers. These companies were ranked by engineering professionals, engineering students, and engineering instructors and professors. Does your employer make the grade?
Sherlock Ohms highlights stories told by engineers who have used their deductive reasoning and technical prowess to troubleshoot and solve the most perplexing engineering mysteries.
While every company might have their own solution for PLM, Aras Innovator 10 intends to make PLM easier for all company sizes through its customization. The program is also not resource intensive, which allows it to be appropriated for any use. Some have even linked it to the Raspberry Pi.
The demand for solar energy around the world will grow a total of 75% by 2019, according to a new report by Lux Research. Trade disputes and policy changes, though, will complicate the picture.
Using a 3D printer, CNC router, and existing powertrain components, a team of engineers is building an electric car from scratch on the floor of the International Manufacturing Technology Show in Chicago this week.
More:Blogs|News
Design News Webinar Series
9/10/2014 11:00 a.m. California / 2:00 p.m. New York
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
7/17/2014 11:00 a.m. California / 2:00 p.m. New York
6/25/2014 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Sep 22 - 26, MCU Software Development A Step-by-Step Guide (Using a Real Eval Board)
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: September 30 - October 2
Sponsored by Altera
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service