Summary for reverse-anodizing aluminum Discussion
Aluminium anodizing followed by reverse-anodizing is not described as a known way to rebuild a fresh aluminum layer on top of anodic oxide. Seid Zafer asked whether an anodized aluminum part could be stopped or reversed and then “re-aluminized” without removing the anodic layer, ideally by an anodizing/reverse-anodizing route rather than conventional plating. Ted Mooney replied that aluminum can probably be deposited over anodizing by other means such as vacuum metalizing, IVD, hot-dipping, or cladding, but he was not aware of any chemical or electrochemical process that converts anodizing back into aluminum. He invited other readers to weigh in, but his practical guidance was that the requested conversion route is not known. The thread therefore points away from reverse-anodizing and toward separate deposition or cladding methods if an aluminum top layer is needed.
November 12, 2019
Q. Hi All,
I hope you good people can help me with my quandary?
I am a researcher and student,
If I am to anodize a piece of Al (any alloy) hard or soft,
is there a way I could stop/reverse and “somehow”
re-aluminize the piece on top of the Anodic layer?
My intention is NOT to remove the Anodic layer but more to introduce another layer on top of it made up of Al:
######## New Al layer
======== Anodic layer
######## Original Al substrate
I am aware that this might lead to going down the route of Electroplating/Electrodeposition/electrolysis,
but I prefer to do it via the anodizing/reverse-anodizing route if I can.
Great forum – BTW, thank you to all who made it possible,
Regards,
Seid
Seid Zafer
University of Bouira – Algeria/U.K.
A. Hi Seid. Aluminum can probably be deposited on top of the anodizing — perhaps by vacuum metalizing, IVD, maybe even hot-dipping or by cladding. But to my knowledge no one has chemically or electrochemically converted anodizing back to aluminum. I don’t know whether other readers can offer encouragement or not.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
November 2019
November 24, 2019
Q. Hi all,
I hope you good people can help me with this,
A freshly anodised and dried sheet of aluminium dipped in an ionic liquid with viscosity similar to that of vegetable oil,
how can I seal the liquid in the pores without the use of water?
the liquid in question can withstand temp of 150 °C but it decomposes in contact with moisture of any kind.
Many thanks
Seid zafer [returning]
University of Bouira – Algeria/U.K.
A. Hi again, Seid. If you’ll take the time to explain what you are actually trying to do, things might be more productive 🙂
For example, what you mean by ‘seal’ is a bit vague: to anodizers ‘sealing’ means a water immersion process which swells the top of the pores to close them off — so inquiring about sealing ‘without the use of water’ is nothing but an oxymoron. But to others the meaning of seal is much broader and could include a lacquer or clearcoat. So, would a non-aqueous clearcoat satisfy your needs, or is swelling the top of the pores with aluminum oxide/boehmite and similar compounds essential? Thanks.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
November 2019
Thank you – Ted,
for your quick reply, I did not know about Lacquer sealing.
Seid Zafer [returning]
– Bracknell, Berks, UK
November 28, 2019
Nadcap Chemical Processing Auditor – PRI, traveling
Process Engineer / Chemist – Denver Metal Finishing, Colorado