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Electroplating copper onto aluminum

2007

Dear Associates:

We have a small family start(ing) up company. Our company deals with the aerospace industry, in particularly rocket propulsion. Recently, we have a particular experimental case where we are wanting to electroplate copper onto a t6 6061 aluminum conical frustum with milled slots. Some of the aerospace companies filled the milled/machined slots with a type of wax and then dipped into the bath of solution for plating. I talked to a head engineer at Aerojet today at a seminar here at the university and he stated that he remembered they used a wax with electrolyte properties to adhere the first layer.

The question(s) are:

Q1: can you electroplate copper onto aluminum?

Q2: what type of wax is it and/or can we purchase/make it?

Q3: for copper/aluminum, do we have to special permits for particular solution(s) with such a small tub for this experiment? (2 ft x 1 ft tub).

Q4: What chemicals would we use for copper/aluminum.

Typically, the aerospace industry electroplated nickel onto a milled copper nozzle, but we are doing a aluminum liner instead that is milled and to electroplate copper onto it.

Thank you anyone for your time and patience and eagerly awaiting team of undergraduates:O)

Respectfully,

James Robert Stoffel
Undergraduate/Aerospace/rocket propulsion - Seattle, Washington

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Plating copper (or other metals) onto aluminum generally requires an entire processing line. Omitting intermediary rinses, these usually are: Detergent clean, alkaline etch (optional), deoxidize/desmut, zincate, cyanide copper strike plating, copper plating. Many environmental concerns. For more details, see ASTM B253, 'Standard Guide for Preparation of Aluminum Alloys for Electroplating' which you can buy separately or find in ASTM's Annual Book of Standards, ASTM Volume 02.05. Alternatively, phosphoric acid anodized aluminum (ASTM D3933-98) has been used as a plating substrate (mostly, pre-WW II).

Waxes used as maskants prevent areas of metal from etching, anodizing, plating, etc. Doubtful that any plated-over wax belongs in a rocket motor! Perhaps you spoke with an engineer in management, far removed from metal coating processes.

Best find a local plater capable of plating onto aluminum.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2007

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2007

Actually, waxes have been used, some particular type of wax with electroconductivity, in order to plate, but.... the wax is removed by other methods after plating the outer jacket/shell of the combustion chamber/nozzle. According to Dr. Zube of Aerojet, thats what they did. Armadillo was attempting a similar process, but didn't plate, but covered the inner milled channel combustion chamber with a solid jacket lathed or composites.

Thank you again for your input! This sounds like a job to send the chamber into some professionals regarding this.

Respectfully,

James Robert Stoffel
- Seattle, Washington, United States