Where the
world gathers for metal finishing
Q&As since 1989


-----

Deionized water cause aluminum oxide film contamination on parts

2003

Our electronic assemblies are being tested in environmental test chambers which use deionized water as the source for humidity testing.

Recently we had problems where an aluminum oxide film has been deposited on parts surfaces which has caused failures.

Can the deionized water used in the chamber cause leaching of aluminum or outgassing or migration of aluminum parts used in the assembly which then can cause aluminum oxide film contamination on parts?

Thanks very much for your input.

Scott Nichols
Electronics - Kokomo, Indiana, USA

I would check out how you are getting your deionized water. Some process of DI water uses salt as a softener. This would speed up the break down of Al. I know that in case of medical parts they would use clean steam as a possible testing technique.

Mike Crabtree
Surtronics Inc. - Raleigh, N.C. U.S.A.
2003

DI water is also known as hungry water, it is corrosive. Race teams use DI water for the cooling in race cars because it conducts heat well. They must drain the cooling systems after practice, qualifying and racing because it will eat up the aluminum radiators.

Todd Osmolski
- Charlotte, North Carolina, USA
2003

Not all DI water is created equal. It may be helpful to review ASTM D1193 - DI water used in laboratory corrosion testing cabinets is Grade IV.

Harold D. Hilton
- Chicago, Illinois, USA
2003