# PVD Gold Coatings



## goldsilverpro (Oct 13, 2012)

I'm writing this as a warning to gold scrap buyers. This stuff looks and wears like thick gold plate, but it really isn't.

I just read about this process. PVD stands for Physical Vapor Deposition. It is a method, mainly for jewelry, for getting long wear from thin gold. It seems to be quite popular. They first vacuum deposit a micron or more of titanium nitride (TiN) on the object. The TiN deposit is fairly rough, very hard, and a golden color - same stuff you see on some more expensive drill bits. Then, a thin layer of gold is vacuum deposited, which fills in the rough TiN surface and smooths it out. The only reference I found for the gold thickness said it was from 6-12 millionths of an inch thick - about $0.10 - $0.20 per square inch at a $1750 spot. It may average less, though, since the gold may not be uniform, especially if the object has been worn. One reference said a few millionths of gold applied in this manner would wear like 10 microns of real gold plating.

https://www.google.com/search?q=gold+pvd&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a

Thinking of a way to test for this, you might simply rub the object on something hard, like steel. I would think the harder TiN would scratch it.


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## leelandbullock (Oct 13, 2012)

one of the many reasons i dont mess with plated scrap jewlery i have read things about this before. but go to a yard sale pick up a bunch and tell them its for your kid or something and you give em 5 dollars for big box and usually they will take it to get rid of it. then its more worth it.


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## Marcel (Oct 17, 2012)

Hereaus has invented such a process and demonstrated it at an electronic fair in munich. The gold is so thin that you can produce foils that you can look trough as if there were not there.


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## mls26cwru (Oct 17, 2012)

Plasma Vapor Depositions are actually what I do at work.... these thin film coatings have some pretty interesting applications, although it is a rather intensive undertaking to get one of these kind of systems up and running. I dunno why anyone would want to do gold plating like this because there are many more lucrative things you can do with this. I do know that the control you have with these systems allow you to put down coatings in the angstrom range. We do optical coatings mostly, but we do have some application for gold platting. these applications are mainly for bus bars and contact points... best way to think of it is like gold fingers for pci cards in computers... there is always a hard under-layer for durability purposes and depending on the specs a relatively thin coat of gold.

***i dont think anyone would coat gold like this with the intention deceiving people, the real application would to be to make the coating more durable.


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## nickvc (Oct 18, 2012)

mls26cwru said:


> Plasma Vapor Depositions are actually what I do at work.... these thin film coatings have some pretty interesting applications, although it is a rather intensive undertaking to get one of these kind of systems up and running. I dunno why anyone would want to do gold plating like this because there are many more lucrative things you can do with this. I do know that the control you have with these systems allow you to put down coatings in the angstrom range. We do optical coatings mostly, but we do have some application for gold platting. these applications are mainly for bus bars and contact points... best way to think of it is like gold fingers for pci cards in computers... there is always a hard under-layer for durability purposes and depending on the specs a relatively thin coat of gold.
> 
> ***i dont think anyone would coat gold like this with the intention deceiving people, the real application would to be to make the coating more durable.




When they make tungsten gold plated bars and coins and fill silver bars with lead..... Oh yes some con artist will no doubt have a go if they haven't already, just remember gold and silver are money in its purest form and people will do just about anything for money.


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## goldsilverpro (Oct 18, 2012)

mls26cwru said:


> ***i dont think anyone would coat gold like this with the intention deceiving people, the real application would to be to make the coating more durable.


I wasn't inferring that. I know the purpose is durability. I was just saying that people could be fooled by the appearance and think the gold is thicker than it really is.


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## mls26cwru (Oct 18, 2012)

goldsilverpro said:


> mls26cwru said:
> 
> 
> > ***i dont think anyone would coat gold like this with the intention deceiving people, the real application would to be to make the coating more durable.
> ...




I was just refering to my comment earlier in my post about 'not knowing why people would do it.' good post though. anything like this brings more knowledge to the table and helps us as a community. It is just interesting to me to see the applications of what i do in different areas 




nickvc said:


> When they make tungsten gold plated bars and coins and fill silver bars with lead..... Oh yes some con artist will no doubt have a go if they haven't already, just remember gold and silver are money in its purest form and people will do just about anything for money.



to do these kind of coatings is a huge undertaking... we are talking stainless steel chambers that are inch+ think attached to all the expensive control equipment needed, cryogenic pumps, etc... These systems can easily cost 1/2 a million... and that being said, the coatings can only be deposited slowly and only so thick... coating something to rip people off for a couple dollars doesn't make a lot of sense when you can easily turn a couple million running a legitimate business....

of course, as I always say, never underestimate the stupidity of the general population...


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