Argentium surface passivation heat treatment

Jewelry Discussion
21 
I have spoken to Peter Johns about hardness - he has advised that
heat treating standard sterling will achieve approx. 65HV whereas
heat treating Argentium will achieve approx. 100HV. By work
hardening the Argentium you can achieve between 150-180HV.

Rubbish as my friends in the UK say. Those that are in love with
Arrgentium tend to try to make it into some kind of super alloy that
is better than standard sterling in every regard. It has some
excellent features tarnish resistance, no fire stain) but its
mechanical properties are not better than standard sterling.

From tests and reports done by independent research (Not in the
business of selling or promoting Argentium)

Standard sterling 925 Ag 75 Cu
Annealed : 56HV-66HV
Aged (heat hardened) : 120HV-140HV
Cold Worked : 140HV-180HV

Argentium 935
Annealed : 60HV-70HV
Aged (heat hardened) : 100HV-120HV
Cold Worked : 150HV-160HV

Argentium and standard sterling are very close in performance in
regards to annealed softness and standard sterling is modestly
better than Argentium in age hardening and cold work hardening.

For comparison to a few other metals

18k Yellow (750 Au, 125 Ag, 125 Cu)
Annealed 150HV
Aged 230HV
Cold Worked 212HV

22K Yellow (971 Au, 55 Ag, 28 Cu)
Annealed 52HV
Cold worked 138HV

18K Ni White (750 Au, 3.25 Zn, 14.75 Cu, 7 Ni)
Annealed 208HV
Cold worked 254HV

James Binnion

22 
No matter how cleanand polished any item is. It will always cause a
polishing cloth to pick up black or grey color. 

That is not tarnish that is the nature and character of the metal
Silver.

Using metal polish on any metal will cause the cloth/wheel to turn
grey/black, because the cloth/wheel loaded with polish is actually
picking up metal particles. It’s basically very fine swarf. Perhaps
the technical support at Rio Grande should learn to explain things
in a more technical and correct manner?

Helen
UK

23

Hello Hans,

Not to worry, the germanium oxide will reform on the surface of the
ring giving it protection from tarnishing. Make your customer aware
that some hand sanitizer or Windex with vinegar will remove early
signs of tarnish.

Jeff Herman

24 
Rubbish as my friends in the UK say.

I wish we could find another term for age hardening that everybody
who is not a metallurgist can understand. You can see the confusion
it causes on this forum. Jim quotes one set of figures for hardness,
I quote another. When I quote hardness numbers I never quote the
traditional two stage precipitation hardening process. Despite being
around the trade for fifty years as a silversmith, I have never known
anybody in the UK harden standard sterling in a small workshop by
that method. They either do not have the equipment or their work is
not designed to take the high temperatures and quenchcooling from red
heat. When I discovered that Argentium seemed to harden very easily
at a low temperature and even after a slow cool in air, I was quite
excited. My next was thought was well not everybody has a kiln in
their workshop, can this be made to work in a domestic oven at 220
428F. This is maximum temperature of our European made kitchen oven.
Theanswer was yes it did, it did not take long and the hardness was
quite good. I have no interest in claims and counter claims, I just
lay out my facts for those who are interested. Your mileage and
experience may be different.

Peter

25

Thanks for all the great info on heat-hardening and increasing
tarnish resistance in argentium sterling. Richard mentions hyperfin
and blue hubble polishing compounds.

Hyperfin or blue hubble are very good for Argentium.

I have found them available only through Australian websites. Are
there any U. S. suppliers? Are these compounds appropriate for
regular sterling and other metals.

Thanks,
Carol McKay
White Rabbit Designs

26

Hi Hans et al

Six months later the ring has some tarnish on it, so you polish it.
The germanium layer is gone.

The tarnish is minimal and easily removed with a polishing cloth.
Argentium naturally passivates to the germanium will rise to the
surface in a few days. Heating speeds up the process. Also a
polishing cloth with thiol (Goddards) with help the germanium to
oxidize.

all the best
Richard

27 
Those that are in love with Arrgentium tend to try to make it into
some kind of super alloy that is better than standard sterling in
every regard.

I was told I painted with too broad a brush here and in doing so
hurt some feelings. I will try to amend.

Those who are over zealous in their love of Arrgentium often tend to
try to make it into some kind of super alloy that is better than
standard sterling in every regard.

James Binnion

28

Hi all

So it [Argentium] is just the same as normal silver? I mean, it
still tarnishes eventually, so what's the big deal?

The big deal, no firescale, easier to work than sterling when
annealed, attains a very high polish and is whiter than any other
precious metal.

It looks better than sterling, according to my customers.

Also the trademark stamp is a flying unicorn, very distinctive and
popular.

all the best
Richard

29

Hi

Rubbish as my friends in the UK say. Those that are in love with
Arrgentium [sic i. e Argentium] tend to try to make it into some
kind of super alloy that is better than standard sterling in every
regard. It has some excellent features tarnish resistance, no fire
stain) but its mechanical properties are not better than standard
sterling.

Bullsh*t as we say in Australia. Annealed Argentium is easier to
work it can be worked for longer, much longer than sterling, before
re- annealing.

It is faster to clean up with sandpaper and faster to polish.

An example. I make mobius rings from 4 by 2 mm oval wire.

In sterling ring needs to be annealed twice.

Sanded with 600 grit then 1200 grit.

Polished/cut with tripoli then with finished with Hyperfin.

In Argentium only one anneal.

Sand with 1200 grit only.

Polish once with Hyperfin or blue hubble.

So half the fabrication time, better than sterling in every regard.

Also it is easier to set stones in Argentium as it is softer than
sterling so bezel thickness of.8 mm can be pushed over by hand
whereas I would need to hammer set with.8 mm sterling. By using
certain stones the piece can be put in a cold oven, to avoid thermal
shock, set at 250 C and turned on and when reaches temperature left
for two hours. Argentium comes out harder than sterling, the figures
I have found vary, but even if it was the same as sterling you have a
thicker bezel that went down onto the stone very easily.

Better to set with than sterling in every regard.

but its mechanical properties are not better than standard
sterling If by "mechanical properties" you meant durability then
obviously polishing with a cloth removes much less metal than
polishing on a buff.

The tarnish resistance and easy to clean make for a far superior
metal from a customers point of view.

all the best
Richard

30

found another supplier of Argentium in Australia who is importing
from the US. Has technical info wrong. Says Argentium is 92.5% silver
and this is what the US supplier says it contains.

There is wrong on the RIo website, I think it is a typo.

Any info would be good.

all the best
Richard

31

Hi

I have used Hyperfin for 25 years on sterling and it works very
well. Never tried blue hubble on sterling as I now use Argentium.

I don’t get a lot of cut with blue hubble because I use an
unstitched swansdown buff and polish lightly.

I am not sure it is worth the cost however. Hyperfin is very good
value and will last many times longer for a fraction of the price.

all the best
Richard

32

Hai,

The casting jewelry master can be made by Argentium instead of
Silver. Due to the Silver master having tarnish some time back.

Please suggest…
Anand.

33

The Argentium that Rio Sells is 93.5% pure silver. With a purity of
93.5% pure silver, Argentium meets the legal standard to be
quality-marked as at least sterling silver. The higher pure silver
content along with the germanium help make it resistant to firescale
and slow to tarnish. We regularlytest and verify the metal quality
of the raw materials in our inventory.

There is actually good info available on our web site under the more
info tab.

Our site states this along with other technical info.

With 93.5% pure silver, Argentium meets the legal standard to be
quality-marked as sterling silver. All Argentium is made from
reclaimed silver and its sources are guaranteed by Argentium
International Ltd. It also welds flawlessly and is ideal for
fusing techniques"

Some random importer may just have their info wrong or they are
trying to take the safe road without checking their facts. Argentium
that Rio Grande sells is at least 93.5% pure silver.

If you do find incorrect info on our website, please let us know so
we can get it corrected right away.

Phillip Scott

Technical Support
Rio Grande
1.800.545.6566

34

Peter,

I wish we could find another term for age hardening that everybody
who is not a metallurgist can understand. You can see the
confusion it causes on this forum. Jim quotes one set of figures
for hardness, I quote another. When I quote hardness numbers I
never quote the traditional two stage precipitation hardening
process.

Standard sterling will respond to the same aging treatment as
Argentium without the requirement for a Solution Annealing stage.
See Dr. Jorg Fischer-Buhner’s paper in the 2003 SFS proceedings “An
Update on Hardening of Sterling Silver Alloys by Heat Treatment”.
The hardness increases of up to 40 points HV he got from as cast
standard sterling items without solution annealing indicates that
though one gets greater hardening performance from a solution
annealed item it is no an absolute requirement to solution anneal to
gain increased hardness. There is empirical evidence for being able
to gain in hardness of a fabricated item in standard sterling by
aging to the same temperature range and duration that is used for
Argentium. What is lacking is numbers to go along with it.

So here is a proposition. We agree on a simple fabrication in
Argentium and standard sterling. Have the raw sheet and wire etc.
tested by a third party for starting hardness. Have you or the smith
of your choice fabricate the item in Argentium and I will make it in
standard sterling. Have them both tested again by the third party
for hardness after fabrication and then have a third party do the
aging treatment and final hardness test. We can write it up and post
it here in a blog or offer it to the Santa Fe Symposium as a paper
on studio results.

Regards,

Jim

James Binnion

35

Hi Carol,

Hyperfin or blue hubble are very good for Argentium

Don’t worry about not finding those particular polishing compounds
in the U. S .The reason Richard uses those is because it has been
suggested that the iron in red rouge may affect tarnish resistance.
There are many other colors of rouge available here in the US–blue,
green, white… Zam is preferred by some. Some people like to use
the liquid form of Goddards Long Shine Polish on their polishing
wheels.

thiol-containing polish, such as Goddard’s Long Shine, or the new
Argentium Silver Care cloths (available though Rio Grande) I have
found Argentium Sterling to be highly tarnish resistant. I have been
using Argentium Sterling since 1999, and I have been extremely
pleased to have my cleaning and re-polishing chores drastically
reduced.

(By the way, these thiol-containing products help protect against
tarnish on all silver alloys. The Goddards products have been around
for many years.)

These are my experiences, and my opinions. I respect the right of
anyone to politely disagree.

Cynthia Eid

36

Professional music restoration artisans in the USA use Blue Hubble
and Hyperfin. A good music store that specializes in wind instruments
may stock it. Just don’t say it’s for jewelry or the price may
increase!

Charlie

37

Jim, Argentium International has published for many years that its
alloy can be hardened in a domestic oven. If craftsmen have also
tried this method with standard sterling and it has worked, then I
am pleased to have publicized this way of hardening—helping all
who work with sterling silver alloys.

My main point for writing to Orchid was to ask that we are clear in
our posts about which heat hardening method we are talking about.
Most importantly, let’s not confuse people by giving hardness
numbers achieved by a method that is not practical for most people on
this forum to use, since it requires expensive equipment not
commonly found in most craft jewellery studios.

Respectfully,
Peter

38

Hi all

I post about Hyperfin and blue hubble because they are good polishes
and easily available in Australia. And less expensive than the
imported French polishes e. g. Dialux blue.

As Cynthia posts there are good substitutes available in the US.

All the best
Richard

39

I keep seeing people state unequivocally that annealed Argentium is
softer & easier to work than regular Sterling, which has me a bit
baffled. My experience with it was much different.

I’ve had any number of fellow chain-making metalsmiths recommend
Argentium for loop-in-loop chains in place of fine silver because
it’s easier to fuse & makes for a sturdier chain. So, I recently
ordered some from Rio to try out & made a bunch of loops to use in a
demo last weekend at a local art fair. While they did seem a bit less
touchy about fusing than the fine silver, a few of the rings visibly
shrank as they fused. I’ve never seen anything like it, to be honest.
After fusing the loops (20g with 12mm dowel) & pickling them, the
loops would have all been annealed, soft enough for me to squish with
my fingers. Instead, they were incredibly hard & nearly impossible to
work. I had to change the chain I was planning on doing at the demo-
the Pinched Roman, chain #7 in Stark & Smith- & opt for a
double-loop-in-loop because it was it was so difficult to form the
pinched & planished links. I even had the metalsmith at the booth
with me doing the raising demo try to squish the fused jump rings &
he agreed they were tough.

Is it some sort of anomaly or what? 'Cause right now, I am really
not impressed with Argentium at all.

Sharon,
Artist, Metalsmith, Chaos Magnet

40 
Argentium International has published for many years that its alloy
can be hardened in a domestic oven. If craftsmen have also tried
this method with standard sterling and it has worked, then I am
pleased to have publicized this way of hardening---helping all who
work with sterling silver alloys. 

My main point for writing to Orchid was to ask that we are clear
in our posts about which heat hardening method we are talking
about. 

Most importantly, let's not confuse people by giving hardness
numbers achieved by a method that is not practical for most people
on this forum to use, since it requires expensive equipment not
commonly found in most craft jewellery studios.

So kilns are not found in typical studios? Heating an item in the
kiln and then quenching it followed by that domestic oven treatment
is not practical to gain a higher hardness? Or just quenching a
casting at 4 min after pouring and then heating in in that domestic
oven to gain 25 - 40 points HV is not practical? So we should not
provide folks with on how to do things and what the
results are and let them decide for themselves because it might
confuse them? Maybe that is good marketing but not so good for
advancing the state of knowledge in the craft.

James Binnion