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Etching aluminum foil for painting while avoiding embrittlement

I'm trying to etch aluminum foil prior to painting for an electronics application. So far, I've had decent success with a two-step process consisting of degreasing and nucleating etch pits using an NaOH solution at room temperature, followed by rinsing and then etching with an HCl solution at elevated temperatures (60-80 °C). This seems to work very well for adhering paint, but the resulting etched foil becomes very brittle and hard to work with. Are there any additives or alternate etching steps I could try to avoid causing embrittlement?

The paint has to be conductive, so I don't think any sort of anodization would work here.

Larry Weinstein
Engineer - King of Prussia, Pennsylvania
October 1, 2009

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October 8, 2009

Larry

Have you considered a chemical film IAW MIL-DTL-5541 [on DLA] ?

Willie Alexander
- Colorado Springs Colorado