Surface treatment with Nitric Acid

Thanks Alisa,

Trouble is that the part may be stored for up to 6 months so I guess tarnishing could be an issue with nitric acid. Would the acid clean the copper or dissolve away the surface exposing a clean surface beneath? I'm thinking the latter.

I wonder if surface treating the pin by tethering silica on it which can form M-SiOH bonds will help? The surface treatment can be then used to react with epoxy resin.

Thanks Shegufa.

How would you tether the silica? I'm not a chemist, just a slightly desperate mechanical engineer :-) .

Eric,

I can only suggest.

Maybe a sol-gel of hydrolyzed Tetraethoxysilane (TEOS) in acidified water could be prepared. You can dip coat your pin in this solution and then react the epoxy on this coat.

I am not very sure of how effectively copper will form Metal-oxygen bonds with the silicate but you could try this.

The sol-gel technique for such coatings using epoxy is very prevalent for corrosion prevention of metals. It is usually carried out under mild conditions. The covalent reaction should give chemical binding and adhesion as well. I am unsure of the extent of binding for your application.

Please do a keyword search under epoxy-silica, sol-gel, anticorrosion for further ideas that may be relevant for your application. Another keyword might be inorganic-organic epoxy-silica hybrids

I can only hope this is helpful.

Best,

Thankyou Shegufa,

That's very helpful. I'll pass on your suggestion to our bonding experts.