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Electro-plating bismuth-aluminium-copper alloy
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Q. I have a question.
I need to electro-plate bismuth, aluminium, copper on aluminium foil/sheet. This is a experiment on technology you might not understand.
Also, in which acid can i dissolve fine powders of the metals described above to produce plating solution? I was told that I can dissolve some metals in acid and then plate from that solution. But I got a question on it that if dissolve the Bismuth for example and then put in aluminium foil to plate bismuth on, will the aluminium get dissolved in that acid or the thin bismuth layer get dissolved as soon as it get plated on?
Scientific Research - Newcastle Upon Tyne, United Kingdom
+++++A. Hi, Siarhei
You are right that I might not understand the technology of what you want to build. Conversely, you may not understand the technology of plating well enough to achieve what you wish. I think you should go to a specialty plating shop and have them assist you with this project.
I would not say that it is impossible to do what you want to do, but the barriers are imposing even for a skilled electroplater with decades of experience. To try to accomplish this with no electroplating experience is not going to get you anywhere very fast. Some of the barriers are that, in general:
- you can't plate onto aluminum without a zincate pretreatment;
- you can't plate aluminum or any aluminum alloy out of an aqueous solution;
- you can't make up plating solutions for this mix by dissolving the metal in acid;
- you usually don't make plating solutions, you buy them so that you can take advantage of the decades of development effort that preceded your experiment;
- it is difficult to plate binary alloys and exceptionally difficult to plate ternary alloys because of their differing potentials (please review the Nernst equation). Consider visiting a prototyping plating shop and discussing your project with them. Best of luck!
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
+++++A. Siarhei, plating a bismuth-aluminium-copper alloy onto an aluminium substrate is not an easy task. As Ted says, it is impossible to electrodeposit aluminium or aluminium alloys from an aqueous bath - it just doesn't work. However, there is an increased interest in electroplating from "ionic liquids", where the problems associated with aqueous technologies are not found. A couple of British Universities are looking at the technology, so do an internet search and find out more details about it. One of the possible advantages of this technology may be that depositing onto aluminium will not require the usual zincate treatment that Ted quite rightly refers to as being essential for aqueous deposition onto aluminium. Alloy deposition of this type of formulation will be very problematic because of the wide ranging positions of the metals in the electrochemical series, but with adequate complexing, it may be possible.
Trevor Crichton
R&D practical scientist The Pheasantries - Chesham, U.K.
April 28, 2011
Q. I would also be interested in knowing if it is possible to plate bismuth onto magnesium foil. I am looking to experiment and study the effects that annealing has on the diamagnetic properties of the bismuth films. Looked into buying bismuth foil but it is outrageously expensive. Any suggestions would be enormously appreciated.
Rob Harrison- Sydney Australia
January 10, 2012
A. Hi, Rob.
It is difficult to plate onto magnesium, and it is difficult to plate bismuth. So the first question has to be: is an intermediate layer(s) permissible? For example, can we plate electroless nickel on the magnesium, then bismuth on the nickel?
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
January 10, 2012
Hi all, I am looking at plating bismuth onto a piezo transducer disc, similar to those found in musical greeting cards. Would sputtering be a valid choice for my needs, and for bonding bismuth to aluminum as well?
Denny Box- Victoria