Wire EDM 6AL-4V titainium

I have machined it (milling, turning threading , boring), but never had occasion to wire EDM it. Any thing to be leery of? Looking at some 12 inch long parts and 4 inch long parts to quote. NDA prevents posting prints. Nothing fussy about dimensions , the closest is a .506 - .508 hole, otherwise +/- .005" . The parts will be anodized after wire EDM (then some second op milling). Will that be an issue?

I think these parts have been machined instead of wire EDMed in the past (by another shop), but they look like an excellent candidate to wire.

I have wire cut many parts from 6Al4v for the space industry. Cuts great (faster than steel obviously). The one and only thing to be aware of is that the material tends to "close up" on you if you are cutting away a thin section. It does so more than other types of material, IMO.

I had many parts to cut where the tolerance was ±.0002", and I was usually able to hold ±.0001" with no problem.

PM

How tight are the profile tolerances?

Long, narrow parts will move on you ... sometimes quite a bit.

This can be alleviated by leaving hold tabs at both ends of the part.

Some years back we cut some parts from some 1/2" thick that were about 5/8" x 6" with the center 5" narrowed to 1/4".

Profile tolerances were +/-.002".

The customer had wedm capability but could not get a good part and gave up after wasting enough material that they needed us to "save" some of the scrap parts.

Their mistake was trying to cut the profile complete in one go, but they just could not see past doing that to the solution.

We drilled two starts for each part, one at each end, and rough and skimmed the long sides of the parts while leaving them attached at both ends and then cut them off.

No problem.

I think KilrB pointed out something I definitely neglected to mention on larger parts -- the "skin" often has to be cut away in a "pre" cut to get stresses out of the material before cutting any close-tolerance features.

The part below is something I cut for an aerospace company, and sequencing the cuts so the "stressful portions" (that phrase has multiple meanings!) were cut away first was key in making a good part. (all the drops shown in the second photo)

PM

precisionmetal said:

I think KilrB pointed out something I definitely neglected to mention on larger parts -- the "skin" often has to be cut away in a "pre" cut to get stresses out of the material before cutting any close-tolerance features.

The part below is something I cut for an aerospace company, and sequencing the cuts so the "stressful portions" (that phrase has multiple meanings!) were cut away first was key in making a good part. (all the drops shown in the second photo)

PM

Click to expand...

That's some real nice work there.