CVD coatings for tools

[Mark_Zirinsky2]

You know, the value to us as craftspeople for CVD would be for us to
coat our tools with it.

Especially for working lapidary materials with a small flex shaft,
diamond tools work well for many situations, and the ability to coat
my own tools would be interesting.

I have a sputtering chamber, but I have never used it, it is sitting
in a warehouse, is it hard (no pun) to deposit a layer, say, of 100
angstroms? forget the gem properties, for toolmaking this should be
all that is needed.

Mark Zirinsky, Denver

[alberic]

Hi Mark,

Some of the big industrial tool suppliers are already doing tool
bits covered with CVD coatings. Largely for aerospace milling and
turning applications. They’re pricey, but not as bad as the old
solid diamond tools were. I get the sense in looking at their prices
and marketing info, that it’ll be a long time, if ever, before that
technology gets anywhere near ‘desktop’ simple.

FWIW,
Brian

[nick1]

The conditions for coating different meatls and carbon types vary
for each type to be deposited. I have no experience of diamond
deposition but the basics are similar to any other material inasmuch
as C is evaporated in a vacuum chamber from a heated source. It is
correctly a form of sublimation, the C I used to deposit from carbon
rods normally ended up as Buckminster fullerine, although no one knew
it until he did some tests on the allotrope and characterised it.
More commonly we used gold, silver, chromium, aluminium and some
others according to what we were up to. The other important thing to
building up layers is having a miniature coveyor belt system to pass
the item to be coated back and forth under the source. Again, this is
easy as a one directional device to build but for your diamond
building you will need a system that can accurately drive your
substrate at a rate of microns per minute.

Nick Royall

[peter6]

the C I used to deposit from carbon rods normally ended up as
Buckminster fullerine 

How much is that worth per carat? Do you think it exists in nature?

[peter6]

Yes I googled CVD and CVD coatings for tools are well established in
the competitive marketplace. The “tequila diamond coating” as posted
earlier on Orchid is along the same lines is it not? One has to
wonder then if there are not diamond coatings in nature.

[Orchid]

the C I used to deposit from carbon rods normally ended up as
Buckminster fullerine How much is that worth per carat? Do you
think it exists in nature? 

As its only form is a single large molecule it has many applications
but will always be a discrete particle so a cost per carat is
meaningless, particularly as it is actually very easy to make. Can
it exist in nature? it can, but you would be unlikely to find it on
earth as the conditions of formation arent here.

I have also told you not to contact me personally on a number of
occasions and since then have avoided posting on threads that you
have started to avoid giving you an excuse for doing so. Do not email
me directly again and reserve anything you have to say for this
forum.

Nick Royall