"J. Clarke" wrote in message
in.local...
In article ,
says...

"J. Clarke" wrote in message
in.local...
In article ,
says...

"Tim" wrote in message
...
On Fri, 15 Jul 2011 01:51:40 -0400, J. Clarke wrote:

First, this post is going to be somewhat vague as I'm under an NDA
and
can't give much detail.

That said, I have a need to cut 1/16" to 1/4" thick slices off of
irregularly shaped objects composed of 5-10 percent nickel, 1-2
percent
carbon, a few trace elements, and the rest iron. Annealing is not
an
option--they have to be cut as is. The objects may be somehwere in
the
range of 1 to 5 inches in diameter. The kerf has to be as narrow
as
possible.

So far I've been using a diamond lapidary blade and oil coolant but
it's
really slow going and judging from the noises it makes the saw is
not
happy. It'll cut through a lump of slag in a minute or so, but one
of
these puppies takes a half an hour with the same setup.

I was wondering if anybody had any ideas on a better way to go.

Wire EDM? It'll still take time, but the kerf will be narrow!

Wire EDM can slab it off at around 25 in.^2/hr., with a kerf on the
order
of
0.020 in. At those speeds, you'll have a heat-affected zone a couple
of
thousanths deep, so that may be a consideration.

Interesting thought, but sounds expensive. I don't think we've got the
budget for it.

I don't know what shop time is on a wire EDM these days. It was $45/hour
last time I looked, but that was quite a while ago.

Hmm, something to look into. Might be cheaper than me standing in front
of a saw. Thanks.

My guess is that it's the best deal. I don't know what they charge for
waterjet these days. As for laser, expect a very rough cut on the downside
of the workpiece, and a much thicker heat-affected zone (HAZ).

Wire EDM can really rip when you're just cutting straight lines are you
aren't looking for blanking-die accuracies. It will easily hold a couple of
thousandths, and it can do better than a tenth, although that really slows
you down.

--
Ed Huntress