Fusing or bonding different sheets of metal together? (melting?)

I haven't had much luck in searching on how sheet metal can made. In
particular I want to make small sample sheets with a few layers of
metals or alloys. I know this can be done, because for example some
coins are made from 3 metal layers described as 'fused' or bonded
together.

Anyone have any idea or know any books on this subject of metals fusing
(not being alloyed, but just physically bonded together) together?
-Joe

On Sun, 09 Jan 2005 19:40:38 -0800, in "Joe" wrote:

I haven't had much luck in searching on how sheet metal can made. In
particular I want to make small sample sheets with a few layers of
metals or alloys. I know this can be done, because for example some
coins are made from 3 metal layers described as 'fused' or bonded
together.

Anyone have any idea or know any books on this subject of metals fusing
(not being alloyed, but just physically bonded together) together?
-Joe

The process you describe is precisely that used in the technique known as Mokume-gan, a
japanese traditional technique by which multiple layers of different metals are bonded
together, after which they are carved or otherwise cut into, revealing the layers in
varyous types of patterns. the metal is then again flattened, leaving a sheet metal
with the multilayered patterns showing. It can often look quite like a sort of wood
grain pattern, which is what the japanese name describes.

Basically, the process is to first see that the individual metal sheets are very flat,
and very clean. They are then clamped together between heavy steel plates, held clamped
by bolts, and then heated in a kiln to just below a temperature at which they would
start to melt (which must also take into account any eutectic alloys that might form
between different metals in the stack). Differing methods may be used to insure a
reducing atmosphere in the heating, ranging from packing the stack and clamps in
charcoal and then wrapping both with stainless steel heat treating foil, which allows
this process to be done in a simple electric kiln, to the use of gas fired or torch
fired kilns where the flame itself provides the needed reducing atmosphere. The main
thing is precise control of the temperature and time to get full bonding. Because the
non-ferrous metals expand more upon heating than the steel bolts and plates, the stack
is under considerable pressure during the heating cycle, which also enables good
bonding.

Look for books on the subject of Mokume. In recent years there have been several good
ones published.

Peter Rowe

google "mokume gane"
also visit www.reactivemetals.com after you decide to buy it instead of
making it yourself.

Carl
1 Lucky Texan

Joe wrote:
I haven't had much luck in searching on how sheet metal can made. In
particular I want to make small sample sheets with a few layers of
metals or alloys. I know this can be done, because for example some
coins are made from 3 metal layers described as 'fused' or bonded
together.

Anyone have any idea or know any books on this subject of metals fusing
(not being alloyed, but just physically bonded together) together?
-Joe


--
to reply, change ( .not) to ( .net)

Carl 1 Lucky Texan wrote:
google "mokume gane"
also visit www.reactivemetals.com after you decide to buy it instead of
making it yourself.

Carl
1 Lucky Texan

Joe wrote:

I haven't had much luck in searching on how sheet metal can made. In
particular I want to make small sample sheets with a few layers of
metals or alloys. I know this can be done, because for example some
coins are made from 3 metal layers described as 'fused' or bonded
together.

Anyone have any idea or know any books on this subject of metals fusing
(not being alloyed, but just physically bonded together) together?
-Joe



If your needs are simple, ie say 3 metals, then the easiest way is to
use brazing foils 1/1000 in thick . cut to a slighly smaller size than
the metal shapes interleaved with the metals, usually 25/1000in thick.
Flux and heat with a large soft torch and you can make your own. bends
well into bracelet or ring shapes. Any more easyflo brazing solder will
cause it to bleed out over the surface of the exposed metals. A pain to
remove.Only kept one sample tho could have sold it many times.

Made many products using this technique in the 3 following metals.
Stainless steel, brass and copper, also red gold on stainless and gold
on silver.

On Sun, 09 Jan 2005 21:45:32 -0800, in Ted Frater wrote:


If your needs are simple, ie say 3 metals, then the easiest way is to
use brazing foils 1/1000 in thick

Simpler to do, yes, the the results aren't quite as strong, nor as clean looking, as the
slightly different colored layer of brazing alloys shows sometimes, and is more prone to
defects in the bond from bubbles, areas of oxidation giving a poor joint in some area,
or other demons that can cause delamination. Try the diffusion bonding method some
time, ted. You'd be surprised at how easy it actually is once you've obtained the
needed supplies, which amounts to the stainless steel foil (commonly used for heat
treating steel items to avoid excess oxidation. I'd bet you've already got some
suitable heavy mild steel plate stock and matching bolts around. Clean the steets,
stack em together, partially fold the foil around it to help pack powdered or granulated
charcoal around the stack's edges) then finish sealing up the foil pack. Find the
eutectic temps of the combinations of any junctions between metals, which generally will
be below the actual melting points of any of the metals, and fire the whole stack in an
electric kiln at around 50 to 100 degrees below the lowest eutectic point. A bit of
experimentation helps to find exact times and temps, but it's very repeatable, and the
bond strengths you can get well exceed what normally can be had with normal brazing
methods. Obviously, the setup for it takes a bit longer, but not really if one has to
find and order the brazing alloy for the other way. I got this info mostly from Jim
Binnion, a local artist and good friend, well known for his superb work in Mokume-gan.
It really is easier than it sounds, and you can practically do stacks of anything from
two layers up to more than a dozen, maybe even twenty or more, if your steel plates and
bolts and oven will accomodate it. The real key, according to Jim, is that the thermal
expansion of the steel is enough less than the non-ferrous metals that when you start
with the bolts already down fairly snug and tight, then the additional pressures exerted
on the stack by expansion of the non-ferrous metals will create very intimate contact of
the surfaces, and very good bonding, thus no delamination problems in working the
resulting laminate. Note that the steel plates are sometimes, and the bolts always,
single use. The pressures are enough to substantially distort and stretch them, so then
the bolts don't work again. Jim uses nickle super alloys, rather than plain steels
(essentially, high speed steel, I think). Those end up being 20 dollar bolts and the
plates cost even more, but ten they don't deform in use, and end up being reusable many
times.

cheers

Peter

Whilst it is true that steel plates do exert pressure when heated, after a
while the bolts stretch and I would suspect the billet compresses slightly
due to the softer metals during the firing process. To overcome this you
need long soak times in the kiln to achieve bonding. If Jim is using nickel
super alloys maybe this helps to eliminate this, I don't know. I did a
course taken by Jim several years ago and then he was using stainless. Ian
Ferguson uses a solid state diffusion bonding kiln, which uses a hydraulic
ram in a sealed controlled chamber that keeps a constant pressure on the
billet. This reduces the soak time to about 60 minutes to achieve bonding.
The extension rods from the hydraulic ram are made of high strength heat
resistant super alloy "Numonic 90" but then not many people can afford such
equipment. Over the past few years I have had my fare share of failures and
successes with the electric kiln process. The last one that delaminated I
had spent quite
a time forging the billet from 22mm (21 sheet stack) to about 8mm before it
showed signs of delaminating. Nothing I could do would save it, I spent
hours trying to nurse it down. Most of the failures were due to
experimentation with cleaning, pressure and alloys used. If anyone is
interested in Mokume Gane I think Steve Midgett's book "Mokume Gane a
comprehensive study" and Ian Ferguson's book "Mokume Gane" are essential
reading. Just before Christmas I met up with a couple of friends who had
just had a couple of bands made by Jim, they were iron and 22ct gold , the
man is good.

Chris

Peter W.. Rowe, wrote:
On Sun, 09 Jan 2005 21:45:32 -0800, in Ted Frater wrote:


If your needs are simple, ie say 3 metals, then the easiest way is to
use brazing foils 1/1000 in thick


Simpler to do, yes, the the results aren't quite as strong, nor as clean looking, as the
slightly different colored layer of brazing alloys shows sometimes, and is more prone to
defects in the bond from bubbles, areas of oxidation giving a poor joint in some area,
or other demons that can cause delamination. Try the diffusion bonding method some
time, ted. You'd be surprised at how easy it actually is once you've obtained the
needed supplies, which amounts to the stainless steel foil (commonly used for heat
treating steel items to avoid excess oxidation. I'd bet you've already got some
suitable heavy mild steel plate stock and matching bolts around. Clean the steets,
stack em together, partially fold the foil around it to help pack powdered or granulated
charcoal around the stack's edges) then finish sealing up the foil pack. Find the
eutectic temps of the combinations of any junctions between metals, which generally will
be below the actual melting points of any of the metals, and fire the whole stack in an
electric kiln at around 50 to 100 degrees below the lowest eutectic point. A bit of
experimentation helps to find exact times and temps, but it's very repeatable, and the
bond strengths you can get well exceed what normally can be had with normal brazing
methods. Obviously, the setup for it takes a bit longer, but not really if one has to
find and order the brazing alloy for the other way. I got this info mostly from Jim
Binnion, a local artist and good friend, well known for his superb work in Mokume-gan.
It really is easier than it sounds, and you can practically do stacks of anything from
two layers up to more than a dozen, maybe even twenty or more, if your steel plates and
bolts and oven will accomodate it. The real key, according to Jim, is that the thermal
expansion of the steel is enough less than the non-ferrous metals that when you start
with the bolts already down fairly snug and tight, then the additional pressures exerted
on the stack by expansion of the non-ferrous metals will create very intimate contact of
the surfaces, and very good bonding, thus no delamination problems in working the
resulting laminate. Note that the steel plates are sometimes, and the bolts always,
single use. The pressures are enough to substantially distort and stretch them, so then
the bolts don't work again. Jim uses nickle super alloys, rather than plain steels
(essentially, high speed steel, I think). Those end up being 20 dollar bolts and the
plates cost even more, but ten they don't deform in use, and end up being reusable many
times.

cheers

Peter
Yes I do have all id need to run this terchnique.
However it wouldnt be cost effective as a commercial product,
for me anyway.
As I design , make and market my own product retail, its too esoteric a
technique to be appealing to my kind of buyers.
A bit like damascening of steel. a wonderful outcome but uneconomic
to do.
The 3 colour metal 3 layer bracelets and ring sets I made had to be
produced in less than an hour to retail at $50.00 each.
Thats the trouble, economics get in the way of art sometimes.
As to the use of brazing foil it didnt give bubble or other inclusion
problems and also didnt ever crack through or delaminate.
despite serious bending after brazing.Probably because I used the
larger base metal in s/steel, then the brass then the copper.
Tho the rings were the more difficult than the bracelets.
Perhaps I should take a year out and do a full retrospective series of
all the items ive ever made.
Ive enough materials left over to do that!!.
Couldnt we all do with another lifetime? to make all the beautiful
things one dreams about
Guess all one can do is make the most of the one ones got.