Need general info about wire EDMing tungsten

Hi,
I work in a mold shop and while we use wire EDM in various metals, we're having problems trying to wire a tungsten sonic welding horn. We have a Sodick A320. Our longest length of cut would be about 5" and the shortest about 2" No tapers, all straight profiling cuts. I'm only asking for general info here, wire type, diameter, power requirements, feed rates and such. Any help will be greatly appreciated!

Thanks,
t2r

t2r

I have no idea what a tungsten sonic welding horn is, but the bottom line is that you really haven't given enough information on the subject. General information is what you are asking for, but I doubt that anyone could give that with the info that you provided.
How thick is the material? what are the requirements for the part? you can use .012" wire and power it as high as you like while trying to avoid breaks. Feed rates? again, it is up to the material and the machine. not you.
I'd love to help you or at least give you a slightly "edumacated" guess, but too many parameters are missing here.
I am curious though.

Regards

WC in the cutting cond. is tungsten carbide, you know...try that setting yet?
If the thickness varies a lot, order up different power settings in the program,
X1.0
ON010 ( here comes a thinner segment of workpiece
X2.0
ON009 ( getting thinner yet
x3.0 ( and getting thinner...
ON008
X4.0


Etc.

We cut quite a bit of tungsten for welding electrodes, use the same settings you use for steel. On one application we draw after wire cutting @1000 Degrees to help prevent cracking of this electrode when it is being used. Mark

What kind of problems are you having t2r?

Are you cutting pure tungsten or tungsten carbide?

Wire breakage?

Part moving?

Part cracking?

De-lamination?

Not holding tolerances?

Are you cutting through a weld?

Is it a dirty, trashy weld?

You may simply need to allow more skim passes.

Sometimes there is no "easy" fix.

Well???

How's it going???

Haven't tried it yet.....

The wire machine had to be moved to make room for a new VMC we're getting in next week and we'll need to get it set back up after.
Thanks for all replies and "I'll get back to you on that"

t2r

Trubble..

Is your longest length of cut 5" or do you mean thickest material you are cutting is 5". If it is 5" thick - - yikes... its going to take a week of Sundays. Solid tungsten cuts extremely slow.

TMD

TheMetalDoctor said:

Is your longest length of cut 5" or do you mean thickest material you are cutting is 5". If it is 5" thick - - yikes... its going to take a week of Sundays. Solid tungsten cuts extremely slow.

TMD

Click to expand...

I cut all the way up to 8" thick of 99.8% pure tungsten.
These parts go into a quartz furnace and shape the ID of quartz tubing.
As long as the tungsten hasn't been in the furnace to long, it cuts pretty quickly using steel settings and stratified wire.
The furnace runs at 4000F.
Tungsten gets kind of funny after a couple years in it.
Kinda turns into crystal...
Anyhow, that same burn takes four times as long using brass wire.
Takes three times as long using carbide settings.



I have also cut 4" thick Tungsten on Sodick Machines.
Those newer machines with the Esprit on board...AQ-something or another...
Can't remember the wire we used but I'd guess it was brass.
Roughing went okay with carbide or steel settings but was an absolute nightmare trying to skim.
Skim cuts just never seemed to be hot enough to remove the amount of material you were planning on.
If I were you, I'd run steel settings and bump the off-time up 'till you get a stable cut on the rougher.
Hit your geometry with the rough cut only if at all possible.
If you skim, you may want make some test cuts.
A .002" shift skimming a roughed out surface will NOT remove .002"
Can't stress this enough so I'll say it again... Get as much meat off the bone as you can with the rougher..
Include your rougher on all test cuts.
Reskimming a previously roughed out form will not yield the same results as roughing and skimming with a new offset.
They won't be even close!!!!
Am I making sense??

If the tungsten is of fairly high purity (99+ %), steel settings are going to deliver as good results as any others while delivering a much faster cutting rate. Although tungsten is a sintered material, there is no need to even consider the use of "carbide settings". The purpose of "carbide settings" is to cut the carbide material while causing the least amount of damage (also known as binder depletion, leeching, etc.) to the binder material nearest to the EDM surface. There seems to be a common misconception that these settings are beneficial (or even preferred?) in cutting tungsten, however, there is absolutely no benefit to using "carbide settings" on solid tungsten unless you have lots of hours to kill- along with a big wire budget. I would recommend to reserve the use of these settings for sintered alloys, such as carbide, and "mostly tungsten" alloys, such as 95% tungsten-nickel, tungsten-Ti, etc.

do any of you guys work with TAM 1000? or Vista Metals VM-NM-12 (Non-Magnetic)?

I have some on going requirement for drill bushes made of VM-NM-12 or non magnetic equivalent & some rather complex shapes made out of TAM 1000 if any of you are interested in quoting including delivery to the UK?