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Titanium tension set ring


#1

Hi Everyone,

I am trying to place more tension into a 6AL4V grade Titanium
Tension Set ring by heating it. It is not working. The only thing I
am doing is making more work for myself as I have to clean it all
over again.

Can anyone share their secret of how to heat treat titanium to
achieve the correct tension? Is there a formula that one can follow?
Like, heat for 15min. at 700F to get a 300 lbs/sq inch tension.

Is there some formula for gold and silver?

Thanks in advance.
Johan


#2
I am trying to place more tension into a 6AL4V grade Titanium
Tension Set ring by heating it. It is not working. 

While I’m not familiar with that titanium alloy, so I don’t know if
it can be heat treated, I’m wondering what your basis of assuming it
CAN be heat treated to harden it might be. Just curious…

Tension set rings are kind of a special case, needing more spring
hardness than many jewelry metals can be given by heat treating. Some
jewelers seem to be mislead by the assumption that heat treating can
always be used, simply from familiarity with the way steel can be
heat treated. Few jewelry metals behave that way. Sterling silver,
for example, can be age hardened to a useful degree to increase
durability, but I’d hardly call the result enough spring hardness to
make a useful tension set ring unless it’s very heavy guage metal.
Not all yellow golds will age harden much at all unless they’ve got
enough copper in them. Same with palladium white golds and most
platinum alloys.

There is a reason why the folks who developed tension set designes
most sucessfully, such as the late Steven Kretchmer, developed
specialized alloys to work with, or chose which alloys to use with
specific care. Many of the alloys we work with, even if they can be
heat treated to some degree, don’t harden enough to be a useful
tension set ring via heat treatment, and can only be sufficiently
hardened, if at all, by actual work hardening.

Are you sure your titanium alloy CAN be heat treated, or did you
just assume it must be the case? I’m not being critical here, since I
don’t actually know if that Titanium alloy will respond as you wish.
I’m just wondering if you are sure it’s even possible… As I said,
just curious…

Peter


#3
I am trying to place more tension into a 6AL4V grade Titanium
Tension Set ring by heating it. It is not working. The only thing
I am doing is making more work for myself as I have to clean it all
over again. 

You dont need to heat treat 6AL4V Titanium to create more tension.
Simply over bend the ring to increase tension, essentially make the
gap smaller. The high modulus of elasticity that particular grade of
Titanium has lends itself well to the tension setting process.

Here is some good reading on the alloy.
http://www.veridiam.com/pdf/DataSheetTitaniumAlloy.pdf

P@
www.patpruitt.com


#4

Ti 6 Al- 4 V is hardened by heat treating by preforming a solution
anneal at 1750F- 1775F for 1 hr followed by water quench followed by
an aging heat treatment at 900F-1100F for 4-8 hours. After heat
treating you will need to remove a few thousandths (.002"-.004") of
oxidized alpha phase titanium or you will be likely to see some
cracking of the material if you stress it as the oxidized case is
very brittle and hard. The only real way to remove it is chemical
etching as this case is harder than most cutting tools including
carbide. For that you need to use HF or Multi Etch. I would highly
advise the use of Multi Etch but even then significant caution is
advised, read and understand the MSDS.

James Binnion
James Binnion Metal Arts


#5

Hi Peter,

Thanks for taking the time to write. 2 sources I know do it but they
do not want to share the knowledge. Now I am turning to the group,
someone must have some experience heat treating titanium.

Johan


#6
I am trying to place more tension into a 6AL4V grade Titanium
Tension Set ring by heating it. 

Johan - heat treating titanum is complicated, and as I understand it
bar stock is generally supplied pre-treated, so if you have cut your
ring from bar without heating it it may already be as hard as it is
going to get. Here’s a brief introduction to the subject :

http://www.keytometals.com/Article7.htm

What exactly do you need to do to your ring ? Or. what is the
problem you are trying to solve ?

Richard


#7
heat treating titanum is complicated, and as I understand it bar
stock is generally supplied pre-treated, so if you have cut your
ring from bar without heating it it may already be as hard as it
is going to get. 

Thanks to everyone that responded. The majority of my tension set
rings are not a problem.

I have a particular request from a client where the titanium is
about 1.2mm thick, except of course where the stone is. Has anyone
done this with thin titanium? Or what is the thinnest that one can go
with titanium, with the help of heat treating?

Johan.