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Electrodeposition of Molybdenum




Q. We'd like to electroplate pure Molybdenum (1 to 2 mil thick) on a conductive circular disc. Is there any chemical solution available to do this? Any detailed information regarding how to achieve this?

Milton Yeh
photonics - Walnut, California, USA
2005



simultaneous replies

A. There is no known method for electroplating molybdenum from an aqueous solution. However, it can be from a non-aqueous solution, but it is a quite complex and not an easy process. In theory moly should be electroplateable as it is chemically very similar to chromium. Furthermore, it is possible to co-deposit it with other metals, but not by itself. It can be vacuum deposited and that is probably the easiest way. Try contacting Climax Molybdenum, they may be able to help you as they are the world's biggest supplier of the metal.

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2005


A. Molybdenum plating formula:
330 gm Na2CO3
100 gm MoO3
1 lit water
10-20 A/dm2
(according to W.Machu: Metallische Ueberzuege, Leipzig 1948.)
Hope it helps and good luck!

Goran Budija
- Cerovski vrh Croatia


Ed. note: We havn't been able to locate "Metallische Ueberzuege" for sale, nor a public domain e-book, but worldcat.org will locate copies in the nearest libraries to you and, for serious researchers, there is an electronic copy available to library card holders at the Othmer Library / Science History Institute in Philadelphia, PA, USA.

thumbs down signI've tried the recommended German recipe. I have been unable to get any metallic deposit. I'm using stainless steel counter electrodes and trying to plate on copper...typical deposit is very dark brown/black and rubs off (some type of Mo Oxide) while there is a thin layer on Cu that looks blue around edges where highest current density and fades to black and back to copper in the middle but remains shiny as substrate. Only achieved deposits at high current densities > 500 mA/cm^2.

Also tried using a Mo counter electrode. The electrode was Mo foil. It dissolved completely in minutes.

Adam Standish
- Providence, Rhode Island, USA
October 24, 2008




Coating or precipitation aging a plasma torch with molybdenum

Q. I want to run plasma torches at higher currents in order to melt titanium in a plasma arc furnace. The torches are copper. I want to use a moly coating to add capability at higher current densities and higher reflected heat levels. Typically these torches are run at 1200 kW at 3000- 4000 Amps, 30-40 Volts. I need a coating to limit torch tip damage at higher power. Does anyone have an opinion on this? How can copper be precipitation aged with moly? Do I need to plate with Chromium first?

Scott Jackson
- Bonita Springs, Florida, USA
May 26, 2016


A. It should be easy to coat molybdenum by PVD techniques - especially cathodic arc. And, PVD equipment need not always cost millions of dollars. Depending on the application and sophistication and the manufacturer it could vary over a wide range. There are, of course many job shops who would be happy to take up the job when the quantity is good (since PVD is a batch process).

H.R. Prabhakara - Consultant
Bangalore Plasmatek - Bangalore Karnataka India




Q. We regularly thermal spray pure molybdenum on batches of parts with good success. We are however interested to electroplate very thin-aqueous route.
Does anybody have a recipe that works that we could use as a starting point?

stuart black
- Poole, Dorset, England
March 15, 2023


"Electrodeposition of alloys: principles & Practice"
by Abner Brenner

on AbeBooks

or eBay or

Amazon

(affil links)

A. Hi Stuart.
• Conventional electrodeposition from aqueous solutions is not considered possible. But see "Electrodeposition of Alloys" by Brenner for an insightful discussion of the topic, plus of course info on electrodeposition of molybdenum alloys.
• Electrodeposition from molten salts is possible, and scholar.google.com has some good references.
• As H.R. Prabhakara implies, PVD processes may be the best route though.
Luck & Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey


A. Try expired patent US2499807A. Hope it helps and good luck!

Goran Budija
- Cerovski vrh Croatia
March 27, 2023


A. We are always grateful for Goran's terrific postings, but as a practical matter, Brenner's 43-page chapter on Electrodeposition of Molybdenum specifically disavows the worth of that patent, citing a history of unsuccessful efforts to duplicate it :-(
Luck & Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey


A. According to Russian sources 10 gms ammonium molybdate/25 mll hydrofluoric acid / 1 lit water electrolyte can be used, 100 A/dm2, platinized titanium or graphite anodes,10-25 ° temp.


Solvent based solution can be used for plating on copper base (10-50 gms sodium molybdate, 1 lit formamide, graphite anodes, 0,04-0,08 /A dm2, 20-25 °C)

Molten salt electrolyte:

37,5 % potassium chloride/37,5 % sodium chloride/25 % potassium chlormolybdate -- 600 °C / 3 A/dm2

(A.M.Ginberg;, A.F.Ivanova, L.L.Kravchenko: Galvanotehnika, Spravochnik, Moscow 1987, page 318 )

Hope it helps and good luck!

Goran Budija
- Cerovski vrh Croatia
March 29, 2023




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