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Tantalum+Platinum coating

 

We are searching for a method to apply a layer of Tantalum and a second layer of Platinum. Each layer thickness should be 15-25 micron.

Question: Could electroplating be used to achieve this with good adhesion and high density surface?

Thanks!

Stig Motroen
- Hamar, Norway

You will find it near impossible to electrodeposit a layer of tantalum - regardless of the substrate. Ad a valve metal, it coordinates into several multi-valent states, and forms oxides, sub-oxides, sub-sub-oxides (you get my drift) and refuses to adhere, form, or otherwise.

You will likely find that either a plasma spray or sputtering a thin coating of tantalum onto a substrate will work if done correctly, and give you some underlying adherence to the substrate. However, depending on the background medium that is involved in the deposition process, you want to make sure that there is no oxidation of the tantalum, otherwise, the platinum will not adhere, and it will exfoliate (peel) almost as soon as it is put into use. Also, the surface has to have a specific roughness to it or the platinum will not adhere.

A better scenario would be to use some type of tantalum substrate as a solid metal, and then fabricate it to what you want, then plate it. If your worried about conductivity or voltage drop in the piece, have a specialty piece made that is constructed of clad copper.

Tom Baker
wastewater treatment specialist - Warminster, Pennsylvania