Ion Plating (Ion Deposition)

A. Ric,

I assume that you mean ion vapor deposition which is a type of PVD processing. The complete subject of PVD processing is covered in the book Handbook of Physical Vapor Deposition (PVD) Processing [on Amazon or eBay or on AbeBooks --> affil links], Donald M. Mattox, 949 pages, ISBN 0-8155-1422-0, Noyes Publications, Westwood, NJ (1998)

A. There are many manufacturers in the U.S. that will build a system for your needs. Contact www.svc.org to check the list of equipment mfrs, or look into Thomas Catalog for Vacuum equipment.

A. Ric,

If you are not talking about ion vapor deposition specifically I could help inform you about sputter deposition, ion implantation or ion plating.

A. Hello Knud,
You are referring to physical vapor deposition. The part to be coated is put into inert gas (usually argon) with a specified coating material. A low voltage arc at a given temperature is applied to actually evaporate the metal in the coating material. Ionized particles are then increased to a high energy. The coating is achieved by the accelerated particles being bombarded. One drawback to the process is cost, another is the learning curve. I know there is a tight profit margin on electroplated jewelry, no matter how you coat it. It would seem to me that PVD would have too long a return on the investment in the plated jewelry market. I can't comment on better wear resistance for PVD because I've not seen conclusive comparisons.

A. Hi Knud. Mark says he isn't able to comment on the relative wear resistance of gold plating applied by ion plating vs. electroplating, which is understandable.

But I think something may be "falling through the cracks" here which might allow you to be confused or misled by the various claims: before gold is ion plated onto jewelry, the jewelry is often/usually first given an ion plating of titanium nitride (TiN). This is an extremely hard, relatively inexpensive material that looks virtually like gold (you've probably seen it on "gold" drill bits).

When a given thickness of gold is applied to this titanium nitride underplate vs. a shiny nickel underplate, it will certainly appear to last longer on the gold-colored TiN. Further, the TiN is sometimes applied in grainy fashion like mountain ranges. In that case, while the subsequent layer of gold will wear off the peaks of the "mountains" quickly, it may be a very long time before the gold in the valleys can wear away. So ion plating of gold on top of titanium nitride will always seem to last longer and in some cases actually does last much longer.

The above remains a simplification applicable to thin gold plating: It is possible to do traditional gold plating that will last a hundred years: you can see it on old pocket watches, although nobody plates gold that thick anymore because it's too expensive. And you can also protect gold plating with a clear topcoat.

Regards,

A. IPS is ionization plating that is one kind of PVD electroplating technique. It can provide the color of stainless steel. Factory will vaporize stainless steel and ionize it. Then the ionized metal will stick on the product. This is usually used in medium to high quality watch which can provide a longer duration of life. The plating you found is what is called "Tin Brass" plating. It is nearly the cheapest kind of stainless steel COLOR electroplating in the market which is usually used in cheap watches. The lifetime of this plating is only for a few months under wear.

A. I suppose you are being trained in using a (magnetron) sputtering unit. Magnetic field confines the plasma close to the cathode and increases plasma density there. Thus more ions hit the cathode causing ejection (sputtering) of more atoms from the cathode. That means, in effect, the magnets increase coating rate. Sputtering without these magnets would not be of commercial interest as the deposition rates would be too small.
Additionally, in the so called unbalanced magnetrons, the magnetic field helps in ion bombardment of the substrates which can help in getting denser coatings.

A. Coating small parts is indeed an issue though there are people who offer PVD coated powders. There are at least two problems- first- exposing all surfaces of all particles/components uniformly to the incoming flux and second- out gassing or virtual leak of gases trapped in the inter granular space. One possible solution is to use some kind of stirrer or vibrator which keep the particles in a state of continuous motion and agitation so that each one of them spend some time on the surface and get coated from the incoming flux. What is the coating you are looking for - TiN, Cu, Al ...?