I’ve just been wondering as I read about diffusion. I read that the
Etruscan pieces give little evidence of eutectic bonding. “Scanning
Electron Microscope analyses of ancient granulations show however no
difference in alloy between ball, contact point and surface
metal.”(Some Notes On Granulation Article by: Charles Lewton-Brain �
1996) Someone must have attempted, in their search for the
"granulation solution", just plain diffusion without the use of
metallic salts. Presumeably it failed(I don’t read much about the
failed attempts-any sources) Just wondering why. Is it because it
would be difficult to “clamp” the granules to the base? If the whole
piece, granules in place, were encased in clay or plaster(Etruscans
probably had access to some form of this) that expanded more slowly
under heat than the metal could this not create the pressure needed?
Would the problem then be finding a way to place granules while
keeping the contact surfaces necessarily spotless? Please forgive me
if right now my circumstances hinder my being able to experiment on
my own. Soon, with a flame and a hammer my inquisitiveness will yeild
its fruit and I’ll remember to repay my debt to you(though likely
never fully).
Manuel
Silence is the cradle of creation.
Secrets are the children of greed.
Skill is the master’s trademark.
Ad Meiorum Dei Gloriam
The silence is intriguing. What does it mean? Either a good idea
worth trying; a lousy idea not worth answering; or another
granulation thread is of little interest. Well, if it is the las
reason then perhaps this may help. Here are some materials that have
been joined using diffusion:
gold- sapphire
rhodium - copper
beryllium- copper
alumina - inconel
beryllium - inconel
fused silica - tantalum
molybdenum - molybdenum
crystal quartz - stainless steel
machinable glass ceramic - ferritic stainless steel
machinable glass ceramic - stainless steel
alumina- copper
tantalum- copper
alumina - titanium
sapphire - inconel
germanium- titanium
(from website below there may be more.)
Even if this idea of diffusion granulation is not what the Etruscans
used if would blow open a big door for new artistic technique.
Imagine being able to set a stone without a bezel or granulate with
glass, steel or a misture of media. The bond created by diffusion
is extremely strong: for an example of the bond strength examine
http://www.fusion.org.uk/stg/breaking.htm The university of bristol
has developed a benchtop diffusion bonding machine but it seems
rather complex and
expensive.http://www.iac.bris.ac.uk/diffusion.html If the process
could be simplified. There is a brief explanation of the process
@http://www.vacets.org/vtic97/ttnguyen.htm. Here is mentions the
interface being treated with very familiar techniques: " mechanical
machining and polishing, etching, cleaning, coating." There is
usually a vaccuum involved but I have a few ideas as to how it could
be created. The process seems to be well developed already and likely
patented at every level or public domain. This provides a good
setting where the viability for goldsmithing could be discussed and
developed. You are all familiar with it in other jewelry processes.
If it is a lousy, impossible, annoying idea for reasons my ignorance
seemed to have missed then let me know and I can spend time on my
other ideas instead of telling everybody useless things. I sincerely
hope the silence is cradling creation. Let me know if something comes
of it.
Manuel