Hammer suggestions for working on titanium

Well a lot of master smiths will disagree with you. They would
simply say that it was knife grinders making up stories again ;-) 

I have great respect for the forging skills of master smiths but they
are not often trained in metallurgy or physics. The work done on the
edge does help with the mechanical properties of the blade by putting
some work into it but in no way does it pack the crystal structure to
a greater density. The spacing of the crystal lattice is a basic
atomic property, you cannot change it with anything as puny as a
hammer.

James Binnion
James Binnion Metal Arts

Hi Bill,

I’ve seen your hot spun vessels. (I scanned Betty’s Reactives talk
slides for her, so I may have a better scan of them than you do.)
(Remind me later in the summer–after I get done moving–and I’ll
send you a DVD.) I always wondered how brittle those things were.
They looked like one good harsh word, and they’d shatter like
stoneware. When it gets so oxidized that it looks like cake frosting,
it’s got to be on the ragged edge as far as bond strength. Ever drop
one?

As far as Ti and heat, I’m always at sixes & sevens. Yes, clearly it
can be hot worked. I’m never sure how much you can get away with
though, as the oxygen & nitrogen get carried very deeply into the
metal, very quickly. The question is then how brittle the whole body
becomes, not just the fried crust. The evidence of "just doing it"
argues that you can get away with a fair bit, while the metallurgical
purists maintain that any real heat at all will fail the whole sheet.
Clearly, there must be a sensible middle ground, but figuring out
where it lies is not an easy task. Thus do I normally say “no heat at
all”. It’s more conservative, but at least you know your metal will
be sound.

Regards,
Brian.

Hi Charles,

So would from your experience would it be fair to say "that
hammering produces a good result if care is taken, and the
advantage over grinding is less lemel?" 

I wouldn’t say that, because when sanding the sides clean and filing
a chamfer on the edges, I probably produce as much if not more
lemel. I just prefer it really. I always found it very difficult to
replicate hammer impressions by grinding. I found it difficult to
achieve the desired randomness, so just prefer the effect of the
hammer. And in stretching it up to size on the ring mandrel whilst
applying the texture, the resulting ring is perfectly round too.

Helen
UK

I first started out hammering for this texture. Then learned to do
the grinding trick. It is much faster less clean up and no chance
of making the ring too large or distorting its shape. 

So you grind? Don’t you end up with lemmel that way?

Regards Charles A.

As far as Ti and heat, I'm always at sixes & sevens. Yes, clearly
it *can* be hot worked. I'm never sure how much you can get away
with though, as the oxygen & nitrogen get carried very deeply into
the metal, very quickly. The question is then how brittle the whole
body becomes, not just the fried crust. The evidence of "just doing
it" argues that you can get away with a fair bit, while the
metallurgical purists maintain that any real heat at all will fail
the whole sheet. Clearly, there must be a sensible middle ground,
but figuring out where it lies is not an easy task. 

It is amazing how much you can hot work titanium. The oxide layer
actually tends to self limit and once you exceed about 1640 F it has
a phase change that makes it very soft. It is actually softer than
mild steel at the same temperature. The confusion about hot work
comes from welding I think. In welding Ti you need very rigorous
shielding or the joint will be brittle. In liquid Ti oxygen,
nitrogen and hydrogen flow very fast and far and they all are bad
news for Ti but as long as you don’t melt it the hot work is not
nearly such a problem. I routinely work our TI/Zr extrusions hot both
as bar stock and ring blanks.I use a torch or forge depending on the
size and precision I need no problem really till the time to clean
off the oxide layer then you need either nasty acid pickle or lots of
time with abrasives. In the industrial metal work literature you will
find there is a large amount of hot work done on Ti followed by a hot
Hf/Nitric pickle to remove the oxide layer.

Jim

James Binnion
James Binnion Metal Arts

I have great respect for the forging skills of master smiths but
they are not often trained in metallurgy or physics. 

Lol, this can also be said of a lot of jewellers. People look at me
funny when I talk about exotic alloys, you’d come across this a lot
too.

Regards Chales A.

Brian, the wine goblets in that set of pictures looked nasty when we
finished the spinning. A few thousands and the crust was gone and
the alpha case too. Sweet metal under it all. Somewhere along this
train of thought on crystal structure and em-brittlement we should
remember that the writings and specifications belong to the people
that build airplanes and space ships.

You know, I have one vessel I don’t really like… we’ll go see! It
is about.218" thick grade #2 Cp Titanium.

I just dropped it 12’ on to a concrete floor. Sounded like a hammer
head! Bounced up about 10-12 inches. You can not see any mark, crack
or anything else. Did it again, upside down, hit on a protruding
lip.

Not a mark!

Get it hot, beat the crap out of it! Have fun!

When I did these pieces it was with a company that hot spins
titanium seamless pipe fittings. One day they showed me a seamless
titanium pipe “T” joint. From a disk they spun up a tube, drilled a
hole in the side and pulled the center pipe fitting out, then rounded
it all up, all hot. As a single piece of metal it did not need xray
or sonic testing to pass inspection as there were no welded joints.

Bill

Bill, Deborah, Michele & Sharon
Reactive Metals Studio, Inc

So you grind? Don't you end up with lemmel that way? 

Pardon my ignorance, but what is lemmel?

Michele

Hi Jim,

I’ve done some limited hot work on CP1 rodstock, and had variable
results. One that sticks with me was a 2ga round rod, run through a
squaring mill, to end up with a square rod of.200" or so. I needed a
nearly 360 bend in it, so I heated it up with a torch, very quickly.
Got the bend area up to red, and then quenched it in water. Total
time at heat was under 30 seconds. (15-ish, probably.) When I later
needed to adjust the bend angle, the joint area snapped like a dry
twig. I figured having a very thick section, and getting it up & down
fast would limit contaminate migration. Clearly not always. It’
experiences like that that make me very conservative on wanting to
heat Ti in open air.

I wish there were some way to figure out how much you could get away
with.

Regards,
Brian.

Michele, Lemmel is the ‘dust’ created from sawing, filing, sanding,
etc. You must have missed that during my opening lecture on sawing!

Cheers, Don in SOFL

So you grind? Don't you end up with lemmel that way? 

No matter how you do it you will end up with lemmel, swarf or metal
dust whatever you wish to call it. If you hammer you will need to
clean up the ring with a file along the edges from the distortion
induce by hammering. If you are set up for working the metal in
question you will have the appropriate methods for collecting and
saving or disposing of said dust depending on its value or hazard
level.

Jim

James Binnion
James Binnion Metal Arts

I've done some limited hot work on CP1 rodstock, and had variable
results. One that sticks with me was a 2ga round rod, run through
a squaring mill, to end up with a square rod of.200" or so. I needed
a nearly 360 bend in it, so I heated it up with a torch, very
quickly. Got the bend area up to red, and then quenched it in
water. Total time at heat was under 30 seconds. (15-ish, probably.)
When I later needed to adjust the bend angle, the joint area
snapped like a dry twig. I figured having a very thick section, and
getting it up & down fast would limit contaminate migration. Clearly
not always. It' experiences like that that make me very
conservative on wanting to heat Ti in open air. 
I wish there were some way to figure out how much you could get
away with. 

I think you may have had other issues. I just took a piece of.065
grade 2 welding rod and heated it to yellow with a torch and bent it
around a ring mandrel for about a turn and a half, quenched and bent
it back straight cold with no problems. Possibly you did not have
long enough heat time but I bet it was already cracked and bent fine
while hot but failed on the cold bend.

Anyhow I find grade 2 very forgiving of both hot and cold work. Some
of the other alloys are not so easy as you know.

Jim

James Binnion
James Binnion Metal Arts

The work done on the edge does help with the mechanical properties
of the blade by putting some work into it but in no way does it
pack the crystal structure to a greater density. The spacing of the
crystal lattice is a basic atomic property, you cannot change it
with anything as puny as a hammer. 

Sounds rather like someone confusing a finer grain structure with
the structure within the individual grains… Finer grainer structure
means smaller grains/crystals which means more grains/crystals in a
given volume, which some might confuse as greater density…

I’ll take that misconception over some others, like those who think
a light working of a piece of metal with a mallet, without actual
bending or deformation, will somehow “shock” the metal into being
harder.

Or the folks who are sure that you can take an herb or medicinal
infusion or solution, dilute it over and over until it’s a
statistical certainty that none of the atoms/molecules of the actual
theraputic agent remain, and yet they’re sure the remaining water,
now pretty much pure, retains or remembers the original additive and
thus remains theraputic. This belief allows vendors to take a cute
fancy label costing fractions of a penny, slap it on a cheap little
brown glass vial also costing pennies, filling it with what amounts
to almost free pure water, and selling it for a bunch of dollars. And
some novelists think some jewelers are swindlers… Shucks. they’re
picking on the wrong industry. (or one of many.)

Peter Rowe

 Pardon my ignorance, but what is lemmel? 

Lemmel = filings.

You end up with lemmel, when filing, sanding and grinding. Keep
them in jars separated as best as you can, for reclaiming later.

Regards Charles A.

So you grind? Don't you end up with lemmel that way? 

Charles, forgive me for saying so, but you seem to be hung up on the
whole lemmel-producing thing? A lot of the processes we do involve
the creation of lemmel/metal dust/filings - call it what you will. I
don’t think grinding creates any more than the hammering and the
clean- up needed after that.

Perhaps you could try both methods for yourself (with silver or
other inexpensive metal), and let us know which one you prefer? I
think personal experimentation would be a valuable lesson in this
case, because we all work differently, so whilst grinding is best for
some, hammering will be better for others. Hammering is my choice
because it suits the way I work.

Helen
UK

Or the folks who are sure that you can take an herb or medicinal
infusion or solution, dilute it over and over until it's a
statistical certainty that none of the atoms/molecules of the
actual theraputic agent remain, and yet they're sure the remaining
water, now pretty much pure, retains or remembers the original
additive and thus remains theraputic. This belief allows vendors to
take a cute fancy label costing fractions of a penny, slap it on a
cheap little brown glass vial also costing pennies, filling it with
what amounts to almost free pure water, and selling it for a bunch
of dollars. And some novelists think some jewelers are swindlers...
Shucks. they're picking on the wrong industry. (or one of many.)

Apparently the perspective of someone who is known as knowledgeable
in all things jewelry related, but not so much about Homeopathy.

I understand cynicism, I are good at it. If you have not experienced
the beneficial effect of Homeopathy I can understand the doubt of the
efficacy of this method.

However, might I point out that the belief that Homeopathy works and
the belief that prayer works have something is common. Some people
who use Homeopathy experience relief from their symptoms, and some
people who pray have the experience that their prayers are answered.

I have found that discounting the experience of others is not of
great benefit, as I tend to not like my experience discounted.

I have over 40 years of experience of positive results from
Homeopathy, but just like traditional pharmacopoeia, not always
effective. And prayer, as an acknowledgment of the potential for good
to manifest in situations where my mind cannot see good, and good
does not seem to exist in any form or shape at the moment, sometimes
in hindsight I find that it is not that there was not good available
but that I was not available to recognize it.

That’s my story and I am sticking to it.

Richard Hart G.G.
Denver, Co. 80210