I’ve been in the jewelry business for a few years now and finally
purchased a toy I’ve been looking at since I found out it existed. An
Orion Arc Welder.
I’ve recently switched over to argentium sterling as well, but I’m
running into joint issues with the welder. I’m wondering if AS is not
suitable for the welder (which would be sad) or am I just needing
more practice. I’m playing with the silver settings on the welder and
I can’t seem to find a combination that will hold the joints. And
when I do get it to hold, the joints are brittle and snap easily.
What am I doing wrong?
The Orion is well suited for welding silver because it has the
’Pulse Arc’ mode with great power. Zap your silver at this setting
with 25% power or more, a 1 mm electrode, and it will bite deep.
Carefull…the heat wave travelling through the silver will be
strong and it may burn your fingers, and may damage sensitive
stones.
Always test on some scrap before committing to the real thing.
I noticed the same thing happening to me under slightly different
circumstances. I use a Miller Dynasty 200 DX TIG welder. My machine
creates a continuous flow of energy, rather than a pulse, for a
controlled time period. When assembling a piece, I normally will
tack the joint and then adjust the position of the components before
making a permanent weld. This is a great way to get all parts in
perfect alignment. While working with 3 mm square wire in Argentium
Silver, I got fracturing at the outer edge of the heat affected zone
of the weld, where hot met cold. The fractures did not occur until I
was welding the other end of the joint, which was 30 mm away from
the original weld. The work around was to have the joint in
alignment prior to welding, along with allowing the work to get
hotter that usual. I ran the arc along the length of the metal a
couple of times prior to ramping up to create the weld puddle.
Further processes did not cause fracturing. You might want to heat
the entire piece so it’s hot enough that you can’t hold it with bare
hands, but not so much that it would burn you. Many metals weld
easier when they have been preheated. You might consider getting
some TIG welding gloves. I use Tillman brand gloves. They fit like a
second skin and allow you to handle hot work.
There is a lot going on at the atomic level with how the metal
crystalizes after being melted and how the crystals mesh at the
joint. Some of the crystal structure has maintained it original
form. The milling process creates a different structure form within
the metal than the structure of a cold ingot. During welding, the
re-crystalizing metal of the weld puddle, is of an entirely
different form than what it needs to mesh with. Regards, Kevin
Krissy - Argentium welds like 14K. FWIW - I turned my Orion welder
in for a PUK 4. It is a lot more understandable. And brittle welds
happen on all of them - has to do with shielding gas, timing, power
and the cycle of the moon.
I notice on the wikipedia article that Argentinium silver undergoes
superior precipitation and heat hardenning - i.e. the microstructure
changes when annealed to make the piece harder.
What you describe here is similar to what one sees in Chromium
stainless steels - the HAZ undergoes enough heating to cause the
chrome to migrate to hard chrome carbides at the grain boundaries -
this increases brittleness at the GB and reduces corrosion
resistance. This is solved by adding (IIRC) molybdenum
There are other steel alloys - especially hardenable alloys - where
Hydrogen can be introduced to alloy around the HAZ greatly
increasing brittleness - hydrogen embrittlement. This is solved by
heat treating at ~150 oC
I don’t know what is happenning in this case but it may be worth
annealing the alloy at around 150 oC and seeing itf that helps - if
not a strategy around annealing quenching and heat hardenning might
work
Mind you it’s a long time since I worked on this stuff so I’m a bit
(pun) rusty…